How to Play Blues Harmonica

How to play blues harmonica is really easy. You just buy a blues harmonica and play it, right? I'll bet that's not the smart guy answer you were looking. Well, here's the truth, you can play blues on more than just a "blues harmonica."
I play blues riffs on any of seven different diatonic harmonicas. I favor the Hohner Golden Melody harps for single note folk songs and fiddle tunes, and I use these for my blues tunes as well. I have Lee Oskar and Hohner Special 20 harps too. The harp I use the most though is a Hohner 10 hole harmonica called "The Chromonica." This is a great harp that is easy to blow with a good sound.
I bought a book called "Three Minutes to Chromatic Harmonica" written by David Harp. It includes three CD's to help you work your way through the lessons. I'm not yet all the way through the book but I am in the last chapter. I'll be going back again to re-do many of the lessons, and to memorize the riffs. I've done this already and I can see and feel the differences.
So, if you want to learn play the blues on a harmonica, you can start with the harp you already have. If you don't have one, then buy a low-end harp in the key of C to start. It can be a "Pocket Pal" or "Old Standby" by Hohner, or others by Suzuki, Lee Oskar, or Huang to name a few. Get a lesson book with CD's and listen to your favorite blues radio stations. Play along with your CD's and the music on the radio. The key is to practice as much as you can, and above all have fun.