I use my 16' canoe in the spring, summer and early fall in the water supply lakes.
I try to keep it simple but seem to be adding more and more stuff lately.
Just picked up a SitBacker canoe seat for the spring.
The 8# trolling motor was the best thing I ever mounted to my canoe. We hardly touch a paddle all day now. A small deep cycle battery will last several days.
Planning on getting a portable fish finder in the near future.
I use a plastic milk crate with some vertical and angled pvc rod holders.
Paddling.net has some good info as well.
Currently a non-fishing slacker! (not for too much longer)