It's really about what works best for you as a paddler. I started out at 45 degrees and moved to a 30 degree because of wrist pain. I also can't use a 0 Degree paddle to save my life, but there are people out there that like them fine enough.

Paddles in the beginning were traditionally 90 degrees and have since gotten less extreme. The variation on feathers is really up to what the paddler is used to and what they are comfortable with. I would recommend using what paddle feels best for you, I would say that it's likely that as you develop as a paddler the 0 degree will become less comfortable, but I've never seen you paddle.

I would recommend in the beginning to get a "economy" paddle so your swims are at half price, and once you gain confidence and are decreasing your likeliness of losing a paddle in a swim, then you can upgrade to one of the nice "performance" paddles from the manufacturer of your choosing.

The 45 and 30 degree paddles are going to be the easiest to find, 0 degree might be a bit tougher. Also look in the FSBO tab on this website as well as Craigslist, just make sure you know what length you are looking for (you can use the Werner paddles website to help you determine what might be a good length).

All that being said, as you develop as a paddler your taste on length, feather, blade shape, shaft, and construction are going to change. So there is that.

Jim Snyder, one of the founding fathers of squirt boating and freestyle kayaking makes paddles and has a couple of good articles relating to some of your questions. If you want to read some paddle philosphy start with the following.

http://rivrstyx.com/the-feather-rap/

http://rivrstyx.com/stroke-theory/

Poke around his site and you will be able to glean quite a bit of information regarding paddles, kayaking, and river in general.

Good luck and happy paddling.

I'd try to stick with 30 degree staight shaft paddles as those are most common and cheapest paddle for most models of paddle. I've got an older werner for sale *hint* *hint*.