In another topic Grover mentioned cfldb.ca - a site I had never heard of. I thought it was worth a topic of it's own in case anyone else was in the dark about it. According to the site:
"CFLdb is powered by CFL fans and enthusiasts like you who submit information, sources, links, common questions and their answers on CFL topics, report issues or errors and suggest ideas of what they would like to see added. A lone caretaker at this time manages the site with a long term goal of turning it over to the CFL community."
I was able to find a rule book in seconds (I haven't seen one on the league site in a number of years) and all kinds of stats.
I think cfldb is a cool website too, but when I search google for “cfl rulebook” in quotes, the official CFL page below (linking to a PDF of the official rulebook) is the second result. The same search without quotation marks returns the same official CFL rulebook page as the first result: