Watch the Blues for Two online guitar lesson by Mimi Fox from Jazz Performance
I strongly recommend that you learn the melody ("head")to as many blues tunes as you can and eventually start making up your own blues heads. It's common for jazz musicians to make up blues heads right on the spot! This is not as hard as it seems. If you learn many blues heads, pretty soon you will absorb the basic understanding of the blues form and you'll be able to make up your own in the same manner. It's fun! All jazz doesn't have to be an analytical experience the blues takes you to the heart of the music.