Fourtyrulz

I've been playing for a few months now, maybe I can pass off some stuff I've learned:

Do they come in all keys? Yep! You can get practically every key in a diatonic harmonica or you can buy chromatic ones. Most people recommend starting out with a C major harp for learning purposes, but if your goal is play some songs right off the bat get a G, D, A or whatever key you need.
How much would expect to pay? A professional Honer harmonica will cost you no more than about 35 bucks, depending on where you get it. But there are lots of different brands and each have a different sound. The best advice I can give is: Don't start off with a cheapo! You will end up frustrated as hell if you get a cheap plastic toy one, spend the extra 20 bucks now to avoid the aggravation.

Hint: It's not as easy as the pros make it out to be, so don't quit right away. With some practice you can learn to play anything under the sun.

Here's some good websites to help you start out:

http://coast2coastmusic.com/general/learn.shtml
http://www.harmonicaclub.com/common/lessons.htm#1
http://www.volcano.net/~jackmearl/ <---This last site is kind of a hokey "harmonica tab" site but has some easy, cool sounding songs to play. Good luck!

Edit: On the Honer site than vanblah posted, the Diatonic Special 20's and Marine Band brands are the best bang for your buck.

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