I think this is a great intro book on blues playing, and is especially well-suited for people studying on their own. I worked through all the material in the book, and liked it so much I've moved on to Ganapes follow-up, More Blues You Can Use.
The structure of Blues You Can Use is very well done, with concepts introduced in a particular lesson often showing up not in the same lesson's song, but in the song one or two lessons later. He drills heavily on pentatonic scales [of course] with exercises that emphasize learning and playing them all over the fingerboard. The bending and legato techniques standard to blues tunes are all introduced and incorporated into the songs. A variety of typical blues chords are also covered, with some nice progressions demonstrating their use. Music theory is covered but usually stays light-to-moderate -- enough to point one in the right direction, I found.
I found the CD was a great help in learning the songs. If I had only one request, I prefer recordings where the lead guitar can be panned completely in and out, and the discs that accompany these two titles don't do that -- but that's a minor nit, and I'd still rate this material Excellent.