The newer Charlton guides have text definitions of Canadian grades too.
A lot of people refer to this site as well for pictures (scroll down):http://www.coinoisseur.com/GradingCoins.html
It should also be noted that Canadian and US graders may not see eye-to-eye,
and that even within the ranks of skilled Canadian graders, some will be more conservative
IMO, it's good to err on the conservative side, and make your purchases accordingly.