I am standing in a wood with a tall man and a dead pheasant. There is blood everywhere: on my shoes, my hands, my face. Why am I here? Because the man - his name is Leon Durbin - is preparing me for the apocalypse, now.

What would happen if you awoke one morning and everyone was dead? Or if, less melodramatically, the world as we know it - and our teetering financial systems - ceased to function? What if you awoke to find your bubble-wrapped, gilded life was over, and for good? Could you survive? Could I?

I am an urban girl. I have no skills except whingeing and bingeing. I can barely open a packet of Hobnobs without an explosive device. But, unlike you, doomed and dying reader, I have decided to prepare for The End, and I am prepared to share the life-saving knowledge I will accrue. This is your cut-out-and-keep guide to the apocalypse. Put it in a drawer. One day you may need it.

So you wake up; everyone is dead. For the purpose of this exercise, imagine it's like Survivors, the cheap BBC rendition of the apocalypse, where a plague wipes out humanity and then everyone is mildly annoyed that the trains are delayed. We could imagine total financial or ecological collapse leading to the failure of social structures, but let's say it's a plague. So, how long can you stay in your house?

The answer is: not long. According to the people at the National Grid, the electricity will stop. So will the water. These systems have buttons. Buttons need fingers. Fingers need people who are alive. You have a day, maybe two, of electricity. Then you will be in darkness, with no way of washing your face.

What should you do? You can steal food from supermarkets but the rotting corpses on the floor of Sainsbury's will be fetid fonts of infection. And if you try to sit out the plague in your home, you could burn or drown. After a lightning strike, fires will begin and they will not stop. And if you live in London, the Thames barrier will fail without electricity and the low-lying areas of the city will flood.

So you have to leave. But where do you go? The apocalyptic norm - see 28 Days Later and Survivors - is for survivors to sit in desirable country mansions, eat tinned tomatoes, develop post-traumatic psychosis and shoot each other. Never in any apocalyptic scenario in any movie I have seen - and I have seen them all - does anyone try to live off the land. They prefer to feed on the crumbs of the lost civilisation. It never works. How can you rebuild civilisation with tinned tomatoes? You need to grow your own food.

But where? I choose Devon. It is warm and wet and fertile, and I have been happy there. There are cows. This is where I would live off the land, but I need to learn how. This thinking has led me to Durbin and the dead bird.

Durbin is tall and tweedy. He is the sort of man who keeps firewood kindling in his pocket, just in case. He owns Wildwood Bushcraft, a company that explains how to survive if you are dropped into the wilderness with no supplies, no warning and no clue.

Durbin leads me through the spindly, sleeping trees, pointing out different kinds of branch and bush, and their uses. According to him, the wood is a shop that will give you everything you need. "Willow bark can be boiled to relieve a headache," he says. "Yew is for making long bows. Oak is for shelters. Ash is for tool handles. Have you ever had a beech-leaf sandwich?" I don't bother replying.

To be competent in bushcraft, you have to be well equipped: before you leave the city, stop for a saw, chisel, spade, axe and hunting knife. Durbin has them all. They poke out of his rucksack in a manly fashion.

We arrive at a clearing and Durbin demonstrates how to light a fire. He places a small block of wood on the ground and puts a wooden stake on it, point down. He takes a bow, made of wood and string, places it round the stake and, when he moves the bow in a sideways motion, the stake rotates very fast. Its friction with the block of wood magically creates a pile of super-hot matter. It can ignite dry hay or bark. This creates a conflagration that can light a fire.

How will I get water? Durbin runs bushcraft weekends for angry executives here, so he knows where it is. "Water," I cry, lunging at a small stream. "Careful," says Durbin. "We have to filter the water with a sock full of sand. Then we have to bring it to a rolling boil." Why a sock? He ignores me.

Food is harder. It is winter and the countryside is closed for repairs. My two main vegetarian foods, Durbin explains, will be burdock root and hazelnut. Both are high-energy. You can make chips out of burdock and you can boil, mash and dry hazelnut to produce a repulsive kind of biscuit. Durbin picks up a spade and starts digging for burdock. He finds some, but it's rotten. "Winter," he sighs. "Hmmm."

So, with a fiendish flourish, I produce a dead pheasant from my handbag. I had spent the day before negotiating with the Guardian as to the legal and moral implications of murdering a rabbit for the purposes of this article. Finally we had compromised, and I had gone to a posh butcher's in Mayfair and bought this beautiful pheasant for £3.50. Durbin looks impressed. "You have to pull off its head," he says. "Just twist it."

I close my eyes and twist. The head comes off easily; it feels like wringing out a slightly damp scarf. Then Durbin makes a hole in the pheasant's bottom and I stick my hand up and clutch everything inside. Out comes a squelchy mass of once-living flesh. Durbin grabs the heart and cuts it open. "Very nutritious," he says. I am slightly sick in my mouth. I pluck, and soon I have a pile of bloodstained feathers - and a nude bird. Durbin sticks it on a spit over the fire. When it is cooked, we eat it. It tastes slightly of excrement but I still feel strangely empowered. It was much easier than I thought it would be, to rip this bird apart.

I now have bloodlust. I ask Durbin how to trap animals. I could theoretically shoot them, but trapping is more suitable for the lazy or incompetent survivor. He looks slightly nervous. "It's illegal," he says slowly. But I prod and he tells me about different types of trap. I could try the pit trap, he says, where you dig a hole in the forest floor, line it with sharpened stakes and camouflage it. It is for large animals - deer, wild boar, parents, other journalists. There is also the deadfall trap, which is for small animals. They saunter over a trigger mechanism, and a lump of wood falls on their head. Bon appetit and ha ha.

But what would I eat if I couldn't trap? "Bugs," says Durbin happily. "Worms." There are 40 calories in a worm, apparently; this is the equivalent of two Maltesers. "Or snails," he adds. "But quarantine the snail for three days before you eat it. It may have eaten poisonous plants, and you will have to wait until it expels them."

Now you need shelter. If I had the choice, I would probably look for a small stone cottage - hardy and easy to maintain - but if I am foraging, I have to go to where the food is. So Durbin shows me how to make a survival shelter. He hurls logs up against a tree trunk, and covers them with a foot of leaves and bracken and mud. "It is waterproof," he says. I climb in and lie down. It is a hole that only a troll could love. But there they are, the four pillars of survival: food, water, fire and shelter.

The next day, I go to Pullabrook Wood in Devon to practise my skills. It was easy to survive yesterday, with Durbin standing by. Can I cope alone? Pullabrook is a lovely wood, administered by the Woodland Trust. It is full of happy Tories and happy Labradors. But now I have my own mini-apocalypse. I fail at bow drilling. I find a stream, but a happy Tory says the water is poisonous, even if filtered by sock. Why? "Because sheep droppings have contaminated it," he says. Death by Sheep is only slightly behind Death by Snail in the encyclopaedia of embarrassing ways to die.

The first shelter I build is too small for me to enter. My second shelter collapses. I decide to abandon bushcraft. I will try my hand at farming. Woman cannot live on worm alone.

So, a few days later, I am standing inside an Iron Age roundhouse at Butser Ancient Farm in Hampshire. Butser is a project that re-enacts Iron Age life. The roundhouse is huge and round and dim. I feel a bit as if I am standing inside a giant breast. Steve Dyer is the archaeological director. He is tall and red-faced, with a frizzy white beard.

"Roundhouses are easy to make," he says, waving his arms. He points out two animal skulls, tied to the entrance posts. Is that a cow's skull? Dyer grimaces politely. "It's a horse," he says, before proceeding to tell me how to make a roundhouse.

The ingredients are: 27 large oak trees, 60 small oak trees, 100 hazel trees, 100 ash trees, wheat straw for thatching, and animal hair, clay, manure, soil and water for the walls.

You will also need animals. Dyer escorts me to his pigpen to meet two nameless pigs. To domesticate animals, he says, you just have to enclose them in smaller and smaller areas. Provide them with what they need - food, water and attention - and they will obey you. You can then eat them, and peel them, and tan their hides for soft furnishings. But beware of sheep, he says, waving a bright red finger. "I know this guy called Si," he says. "He approached a frisky ram. It jumped up and broke his nose." I am back at Death by Sheep.

I telephone the psychologist Cecelia De Felice. I want to know if I will go insane in my new one-woman world, especially when faced with tasks such as chopping down 27 large oaks. "You will be in a state of trauma," she agrees. "You will quickly become lonely and paranoid. It is possible you will have a breakdown." And if I meet other survivors? Be cautious, she advises. "They too will be lonely and paranoid. Of course you are stronger in a group. But you do not know whether they will help you or just steal your resources. Trust no one."

I am (vaguely) confident I will not starve. But there is one other thing I am sweating over: nuclear power stations. Professor Alan Weisman wrote The World Without Us, a description of what he believes would happen to Earth if we all vanished. I call him. He says I am right to worry. Why? Because most nuclear plants are water-cooled. Water, he explains, in a dry, calm voice, needs to circulate around the reactors, or they will explode. If there were no humans to operate it, the plant would shut down automatically, and the water would be cooled with diesel fuel. For about a week. Then the heat from the reactor would evaporate and expose the core. "It will either melt down or burst into very radioactive flames," he says. So what would you do, Professor Weisman? "I would probably go to Canada," he says. "There aren't many nuclear power stations in Canada."

So, it comes to this. No matter how hard you try, Britain will probably become a nuclear wasteland. The snails that are your lunch will either die, or look very weird. So, again, what to do? My considered advice is this. You, Guardian reader, need to begin building a boat - a sailing ship, actually - to take you to - yes, Canada. Before you leave the city you should pause at a library and steal the entire boat-making and maintenance shelf. Canada may be your only hope of salvation. And that is as fitting an obituary for our civilisation as I can type. In The End, it turns out you don't just have to be the heroine of Survivors. You need to bloody well be Noah too.

Happy apocalypse.

It's not all bad: Fun things you could do after the apocalypse

• Pop into the National Gallery and take Jan Van Eyck's Portrait of a Man off the wall. (If you have no taste, take a Renoir.) The Van Eyck is hanging in the Sainsbury Wing. If you want to preserve it properly, Thomas Almeroth-Williams of the National Gallery suggests you store it in a slate mine, where the temperature and humidity levels are perfect for its conservation.

• Go to the British Library and help yourself to one of its two copies of Shakespeare's First Folio. One is in a box in a strong room under the library floor; the other is in a glass case in the Treasure Room. If you want to preserve it properly, Helen Shenton of the British Library suggests you store it in a cool, dark place, and watch it carefully for infestations by animals or fungi. Dust regularly.

• Steal the crown jewels. If you can. "There are contingency plans in place in event of a power failure," says a Royal Palaces spokesperson, "so the crown jewels should remain safe." Really? To preserve them properly, do nothing. A diamond is for ever.

• Invade the News of the World - it's in Wapping - and read all its secret files. Then break into M15. It's on Millbank. Read all its secret files too. Oh, no! She was murdered! I knew it!

• Go and stand on the stage at the Theatre Royal, Drury Lane. Skip over the bodies of the dead actors. Re-enact the whole of Oliver!

The vital skills you will need

How to make bread

I type this in full because I want bread at The End, and I want you to have it too (should you survive). So, clear the land, turn the soil over to create furrows, take seed from any wheat growing wild, sow it 20cm apart and kick the soil over. Make sure that the birds don't eat the seed.

Stop browsing animals by hedging the field off and root out weeds. When the corn is ripe, thresh it by hitting it with a stick and mill it by rubbing it between large stones. Add the flour to water to make dough. Stick it in a pan on the fire. Result? Wholemeal flatbread!

How to make sanitary products and toilet paper

Find some sphagnum moss and use that. It is very spongy and it contains iodine, so it is slightly antiseptic.

How to eat snails

Always, always quarantine snails before eating them. Take the snail and put it where there is nothing for it to eat. Ignore its cries of hunger, leave for three days and then consume.

How to purify water

Collect the water from the purest source available, ideally a spring, minimising sediment and avoiding chemical contamination. Filter it through a sock full of sand. Sterilise the water by bringing it to a rolling boil for a few seconds.

How to clay bake a fish

Wrap the fish in large leaves, tying up the parcel with nettle stalk. Dig for clay in the earth. After combining the clay with water, cover the fish with a centimetre of clay, leaving no cracks. Scrape a shallow pit in the centre of the fire and lay the fish in it. Cover the fish with embers. After an hour, remove the fish and crack the outer shell open. The fish should be perfectly cooked.

How to remove the skin from a cow

You can kill a cow by strangulation apparently, although I have never met anyone who has done it. Or you can cut its throat, or spear it through the heart. Split the cow along its belly from the groin to the throat. Remove the internal organs. Hang the cow up by its hooves for several days to let the blood run out. Cows are heavy, so do not attempt to do this alone. To take the skin off, slide a blade or a sharp stone between the skin and the flesh. Once you have inserted the tool a little way, you can just peel the skin off.

How to shoot a deer with a bow and arrow

Deer are sensitive to human noise and smell. If you stomp through the wood with a bow and arrow you will never find one. Find out where the deer are going to be - they often walk the same way to the same place. Camouflage your scent, be quiet and do not move. When you see a deer, shoot it from 20m away. You ideally need a kill shot, eg in a lung. You don't want to hit it in the bottom, because it will run off and you won't get your dinner. TG

• Sources: Leon Durbin (Wildwood Bushcraft), Steve Dyer (Butser Ancient Farm) and Ben Jones (Merlin Archery Centre).