This is just the description on the back of the DVD, I have not had time to thoroughly review the complete set.  It is not so much slide guitar oriented as I would have liked, but it appears to be a very good instructional video anyway.  I will get to this in the next couple of weeks and give you my thoughts.

Rory Block - Delta Blues Guitar Vol I - DVD - Now you can learn the classic guitar styles
that influenced countless blues and rock artists, from Muddy Waters to the Rolling Stones. In this video
lesson, one of the most knowledgeable and talented exponents of the classic blues style reveals the earthy,
hard-driving playing of the Mississippi Delta. Here is the powerfully rhythmic "pounding" style of Charlie
Patton, the fingerpicking blues of Tommy Johnson, and the sliding, open-tuned sounds of the great Robert
Johnson, made clear through the magic of video. In a short time you'll be playing great finger-style blues
pieces such as "Moon's Goin' Down, Patton's Blues, Crossroads Blues, Travelin' Blues". As you learn these
powerful songs, you'll be developing technical skills in the use of regular and open tunings, treble melodies,
bass runs, slides, string bending and a variety of amazing pounding and strumming blues techniques.
Rory Block - Delta Blues Guitar Vol II - DVD - In this video lesson, Rory Block continues
her exploration of the earthy, hard-driving blues of the Mississippi Delta as played by Booker White, Robert
Johnson, John Hurt, Charlie Spann, and other great traditional players. She teaches a number of powerful
blues songs, including "Fixin' To Die, Love My Blues Away, Leavin' Here, When You've Got A Good Friend"
and "My Train Is Waiting". As an added treat, Rory strays from the Blues to teach her arrangement of the
great English ballad  "The Water is Wide", one of her most requested songs. Each piece is carefully broken
down to provide an understanding of the styles and techniques of the blues masters. You'll be able to see
both hands in close-up as you learn open tunings, treble melodies, bass runs, slides, string bending and
additional variations on the intros, solos, turnarounds and endings.
(60 min) Booklet