I have done lots of paddling over the years, and still continue to do some. This weekend we just planned a 5 day trip to Murtle Lake, in Wells Grey Provincial Park in BC, for September.
I have kayaked a bunch in the past, both white water and sea kayaks. Both are great for their respective uses. However, I now MUCH prefer to canoe. I find them way more comfortable in that I can change positions as I need, I can take more luxury stuff (well, luxury for backcountry travel), they allow more access to gear as you paddle, with my cameras and lenses at hand. Oh yeah, and Jasper can travel in a canoe.
I have 3 canoes, a fast asymmetrical tripper for flat water travel, which is fast and and paddles easily. I have a river boat with lots of rocker, built tough, which manometers big rapids nicely. My third canoe has not hit the water yet, it is a cedar stripper, a solo tripper for lakes, which I hope to have finished for our September paddle.
The link baglo posted explains the different uses for canoes quite well. If you haven't paddled a lot, and are only looking for something for day trips, something that is fairly stable and tracks well would be advisable. I know my lake tripper makes a poor day paddling boat, as it is designed for speed (a rather relative term), and is very wobbly when not loaded. Others like a Prospecter design, are a fairly stable canoe, and all round performer.
If one does not have the space to put a canoe on the tow vehicle, like with a 5.0, I would not hesitate to get an inflatable canoe. I have paddled in one on a river that was quite nice. I am not certain how much of a pain it is to inflate or deflate though. There are also good folding canoes, and lots of people have used them for fly in paddles.
I have only paddled in two states, Idaho and Oregon, but there were no regulations I know of.
With my brother and niece
With my son and me
Lisa and Jsper