hello ilovestamps,
For Canadian revenues, the best source of information is ESJ Van Dam.
http://www.esjvandam.com/ He's not only a dealer, but the pre-eminent cataloguer of all Canadian material. Another superb source of information and knowledge-sharing is the British North America Philatelic Society's Revenues Study Group:
http://bnatopics.org/hhlibrary/news...rs/n-rev.htm More recent newsletters can be had by joining the study group.
Revenues are a constant fascination for me, though I have thus far avoided jumping into the deep end with them. I'm afraid I'd never emerge!
Peter