Step1
Buy a good blues harmonica in the key of C. The Huang Silvertone is a good starting model if you want to go with something inexpensive. The Hohner Special 20 and Lee Oscar Diatonic harmonica are serious professional models at a reasonable price.
Step2
Learn the single hole embouchure. First, put the harmonica loosely between the lips, then pucker them until you can play one single note by drawing in or blowing out.
Step3
Learn how to draw bend. Start by drawing in on the hole two.
Step4
As you are drawing in, say the word "ear." As you say the "r," you should hear the note drop and feel a change in the airflow. If not, keep trying.
Step5
Learn to control your bend. By varying the airflow and the position of your tongue and throat, you can learn to change how far you bend the note.
Step6
Learn articulation. By mouthing the syllables "tah," "hah," and "kah," you can control the beginning and end of each note.
Step7
Listen to a lot of blues. Include different styles such as Chicago, Piedmont and Delta blues. The more influences you listen to, the better.
Step8
Learn the basic 12 bar blues progression. The link below explains the basics of playing the 12 bar blues.
Step9
Learn the circle of fifths. In blues harmonica, you usually play in a key 5 half steps above what your harmonica is keyed in. For example, a C harmonica plays blues in G, a G harmonica plays blues in D, and so on. This is called "cross harp."
Step10
Get some more harps. If you can afford it, buy all 12 keys. At minimum, however, you should have A, B flat, C, G, D and F.
Step11
Play along with blues recordings. Find what you like and imitate it. With the basic keys you have, you should be able to play along with most harmonica songs.
Step12
Practice every day. Even if you can only spend 10 minutes a day playing the blues harmonica, make sure to do it.
Step13
Go to a blues jam. More experienced harmonica players will be happy to give you some tips to take your playing to the next level.
Novice 
