Online shoppers are expected to spend almost £1billion today as retailers release a deluge of 'bargains' as part of the Cyber Monday shopping event.

Spending is expected to soar by 31 per cent on last year as many retailers offer discounts following on from the Black Friday weekend.

But how do shoppers know if what they are buying is a real deal? This is Money has some tips on how to hold your nerve and check if a bargain is legitimate.

Cyber Monday: Don't get sucked in by a bogus deal, check comparison websites and historical prices before you click the purchase button.

Compare prices before you buy

Before you start shopping download a tool to your browser that will alert you if the price of an item is cheaper elsewhere. The Invisible Hand browser add-on works with Firefox, Chrome and Safari by checking prices at almost 50 different retailers.

If a price is cheaper it will pop up in the top of your internet browser and you will be able to click through to the rival website to view the item at a cheaper price.

The tool – named after the 18th century economist, Adam Smith – doesn't compare the price of postage and packaging, so remember to take this into account when doing your comparison.

All the Invisible Hand tool is useful it's not fully comprehensive, so check other shopping comparison websites – such as Kelkoo and Google Shopping - too.

How to check Amazon's historical prices

On Friday, Amazon reported record sales figures, with more than 7.4million items ordered, leading to its biggest sales day ever. A similar level of shopping is expected today, as the retail giant has released another torrent of offers.

If you're keen to grab a 'bargain' on Amazon then check price tracking website, CamelCamelCamel.com before you click the purchase button – it allows shoppers to see the historical price.

For example, one of the Cyber Monday deals a Kindle Fire HDX 7', HDX Display, Wi-Fi and 4G, 16 GB - Includes Special Offers (Previous Generation - 3rd) is being sold at the Cyber Monday price of £139, a discount on the recommend retail price of £139.

However, by checking the item on CamelCamelCamel.com it reveals that under a week ago, on November 24, it was sold for £119 – cutting the Cyber Monday price by £20.

Historical prices: The CamelCamelCamel.com website reveals if the item has ever been sold at a lower price.

Another item listed as a Cyber Monday deal, the Xbox One 500GB with Rare Replay & Ori is being sold for £223.99, down from £264.43. The CamelCamelCamel.com website reveals this is the cheapest price it has ever been listed on Amazon.

While this may not deter you from buying an item it can give you an idea of if the item is ever sold a cheaper price. The website also allows you to set up alerts for items – so that you can be notified via email when the price drops again.

BEST CYBER MONDAY CASHBACK Quidco: Debenhams: Up to 50 per cent off in the 'brand event', with an additional 10 per cent off on spends over £30. 6 per cent cashback. (Expires: Tonight). Currys: Tons of discounts in the 'Black Tag Event', combined with up to 16 per cent cashback. (Expires: Tonight). House of Fraser: Up to 50 per cent off, with up to 10 per cent cashback. (Expires: Tonight). TopCashback: The Body Shop: Up to 13.65 per cent cashback on a beautiful range of beauty products (Expires: Sunday 6 December). Groupon: earn 11.55 per cent cashback on restaurant bookings, beauty, travel, ticket and shopping vouchers (Expires: Tuesday 1 December).

Don't miss out on cashback

Once you've decided that the item is the cheapest price then the task is to see if you can push the bargain even further by purchasing through a cashback website.

Websites like Quidco and TopCashback allows shoppers to earn money on purchases, just by clicking through a link on the retailer's website.

Both the websites are free to join, however, premium members can pay £5 per year to unlock higher cashback rates and faster payments from retailers.

Most of the cashback payments are usually paid within 28 days of the item being purchased but this varies from retailer to retailer.

Quidco told This is Money that some of its biggest traffic through the site on Black Friday went to the retailers with the best rates.

For example, one of the most visited retailers through the cashback website was Nike, offering 22 per cent cashback on top of a 30 per cent sale.

Swerve delivery charges and get your package in time

One in ten of 40million items ordered on Black Friday and Cyber Monday will arrive late due to the influx of orders, claimed logistics expert Stuart Higgins, from LCP Consulting, on BBC Breakfast this morning.

So how can you avoid the delivery crush? If you're worried about your package remember that the responsibility is with the company who you ordered the package from – not the delivery firm – if anything goes wrong.

If you paid for express or next day delivery and it arrives late then you have the right to claim back this cost from the company.

Many of the larger retailers, such as Argos and John Lewis, now offer a 'click and collect' service which means you can avoid delivery delays – and often costs – by arranging to collect your item from a store of your choice.

Some retailers impose minimum spend, otherwise you will pay for the service. For example, John Lewis charges £2 for order under £30. Shoppers can collect their package from their local John Lewis or Waitrose store.

The service has proved so popular with shoppers that some online shops, such as Asos, now also offer a 'click and collect' service where packages can be picked up from Collect+ or Boots stores.

Shoppers have 10 days to collect parcels from their chosen collection point and delivery costs vary.