A mirthful online guide to marijuana use, put together by police in Seattle, has become an internet hit as the authorities in Washington state gear up for the changes brought about by Initiative 502 – the election-day ballot measure that legalised the drug.

The "Marijwhatnow?" post on the Seattle Police Department's Blotter blog attempts to explain the do's and don'ts under the new measure, which comes into force on 6 December. Employing language that would no doubt be appreciated by a potentially stupefied audience, it has generated nearly 30,000 Facebook "likes", with questions such as: "Will police officers be able to smoke marijuana?" Answer: "As of right now, no. This is still a very complicated."

Among the factors complicating the matter for officials in Washington and Colorado, which approved a similar measure, is that their new state laws are in conflict with federal legislation, which continues to outlaw marijuana. The blog makes it clear that, in Seattle at least, officers will follow state law, which will allow adults over 21 to possess up to one ounce of marijuana (or, as the blog clarifies, "16 ounces of solid-marijuana-infused product, like cookies") for personal use.

That is from 6 December, though. Ahead of that, the blog poses an obvious question: "[that] seems like a really long way away. What happens if I get caught with marijuana before then?" Answer: "Hold your breath..."

Another addresses concerns about seized property. To the question: "[Police seized] a bunch of my marijuana before I-502 passed. Can I have it back?", the answer is a definite: "No."

And if there is any doubt about the tone, the blog features a video of a scene from Lord of the Rings in which Bilbo Baggins is shown enjoying a smoke of what is described as "the finest weed in the Southfarthing".