The Rideau Canal is a great cruise. We did it a few years ago and
still remember it as one of our best trips ever. Their is an
organization called "Friends of the Rideau" that has a lot of good
material:

http://www.rideaufriends.com/

Assuming you go up through the NYS canal system, their guide is also on
the "must have" list:

http://www.canals.state.ny.us/exvac/cguide/index.html

We found that the most difficult charts to get in advance were for the
St Lawrence Seaway area going around Montreal. There is a good chart
book available however from the Canadian authorities that covers that
stretch and a lot more. Unfortunately I do not have it with me at the
moment but I think you may be able to get it he

http://www.pilothousecharts.com/Hudson.htm