There is a section of this forum called RVing in Canada and Alaska:
http://forums.woodalls.com/Index.cfm/fuseaction/listings/forum/65.cfmAt the top of the front page in that section are sticky threads with links to a lot of essential webpages - especially those from the Canadian government with '.gc.ca' in the url.
They tell you regulations for food, pets, tobacco, liquor, firearms, firewood.
& there are a lot of threads where folks have given their experience.
Remember no Border Guard has time to ask about all the things covered by regulations. You could just get caught for thorough search, even if that only happens to a few people. So, prepare for it.
:C