Obviously you don't get here an easy "Dr. John for Dummies" just because this series of books is not made for the regular weekend piano-player. It is supposed to introduce the N'Awlins style of piano playing for the skilled blues/classical/something else pianist.
I've got the VHS versions and well before I got those I managed to learn some Dr. John's stuff by ear, like the "Honey Dripper" (in G, left hand boogie 5ths/6ths pattern) and I found it quite useful when I was learning his version of "Good Night, Irene" because I just couldn't figure out exactly what the left hand was doing, so I watched the video a couple times to get the left hand part and a couple more to get the right hand licks and it was done. Of course he won't play everything here in half-tempo and tell you to add a crushing f# to your g octave so it'll sound more Orleans. Hello, he's Mac Rebennack, aka Dr. John the Nighttripper, he isn't your piano teacher.
Well, you should get this if you are a Dr. John fan or if you are really into blues piano, but don't think this will make you a Professor Longhair. This is an aid, not a pair of crutches.