Here is what you can bring: http://www.cbsa-asfc.gc.ca/travel-voyage/ifvc-rpvc-eng.html#a2
Here are the regulations about food and the other products: http://www.cbsa-asfc.gc.ca/help-aide/faq1-eng.html#_s4
As to Canadian customs, that's a really complicated question. Where are you traveling to? That would give me a better sense in order to answer the question.