Paddling is hard work, so bring large canteens which you can fill each morning with boiled water. Tie the backpacks onto the canoe while paddling. I would hope this one was pretty obvious. You are responsible for keeping the campsites perfectly clean, which means carrying all of your garbage out with you . Use only biodegradable soap.
Some campsites are better than others.
It's a good idea to pick a site and set up camp early, a few hours before sunset. This allows you to pitch tents, cook dinner, go for a leisurely swim, and, most importantly, memorize the path to the latrine, before dark. It'll be might difficult trying to get back to the entry point one paddle short. Lakes are by far the most common feature of Algonquin, but there are also rivers, streams, a few marshes, and even a waterfall or two. On the rivers, expect to encounter beaver dams.