Hello! Yes, there are lots of places to rent canoes - I always use an outfitter that has several store locations around the outer borders of the park:
http://www.algonquinoutfitters.com/
As I live in Toronto, I drive North about 380 KM to get to the 'west gate' entrance to the Park (where you buy a permit to be in the park - quite cheap - go to
http://www.algonquinpark.on.ca/ to learn more about the fees and permit details - you'll want to choose the backcountry sites - as opposed to the drive-in sites - I'm guessing. That's what I use.), and if you are travelling also from the south (Toronto region) about 10 KM before you actually enter the park, there is the Oxtongue Lake location
http://www.algonquinoutfitters.com/about_location.html of the store - go there, and rent a canoe - rates are on the site. Call in advance if you'd like.
Contact the Park officials via their site (
http://www.algonquinpark.on.ca) to get suggestions on routes, locations etc... to camp - they'll answer any questions you have - they have many international visitors travel through each year.
I paid about $90 for a 4 day rental of a canoe recently - paddles, life vest, safety equipment etc... comes included. You can tie it to your car roof, or they will drive it in to a location on a river/lake etc... for you for a minimal fee.
Note location of Algonquin Park in relation to Toronto etc... in this map:
http://maps.google.com/?ie=UTF8&z=7&ll=44.964798,-78.640137&spn=3.839997,7.470703&om=1
Also, feel free to download an incredibly detailed 5Mb PDF map of Algonquin Park I have stored at
http://www.sgjp.com/algonquin.park.map.pdf - I use this to plan my trips!
Hope that helps! Let me know if you have any other questions.
Cheers,
Mungo