I think ebay is probably the best way to go. B & H is good too but I think you'll get a better deal on ebay. I would recommend getting a 35 mm SLR with a metal body. The key being the metal body, there's a better chance a metal body will survive being dropped. Also I would suggest getting a fully manual, that way you really learn how to use your camera in all aspects. I've also heard some people say that autofocus makes them use more film which of course costs extra money.
My sister got her camera off of ebay and you can find good complete cameras for under fifty bucks. I'm actually thinking about doing the same soon, my digital camera is fun but I really miss having a manual, the noises were just so satisfying.
btw B&H is awesome for film (and lots of other stuff too) they have probably every kind of film under the sun.
Good Luck and post your pictures here:
http://www.fotolog.com if you can I'd love to see them!