First of all, like all of the Grimoire series books this one is pedantically thorough. It weighs in at about 248 pages, but the material could probably be covered in a quarter of that. Still, even at the smaller size it would be well worth the price.
The first section presents major scale exercises in F. The reason F Maj. was chosen is that it puts the root of the first movable position on the first fret of the sixth string. At the end of the section diagrams are given for the other roots, but these could be easily derived by moving the forms.
The exercises in this first section have you practice the F Maj. scale three notes per string with economy picking up and down the neck. The advantage of this approach is that if you repeat the exercises the way he describes them (including the picking) you will be playing the major scale very quickly and precisely in no time.
There are some one or two string exercises, coil exercises in three and four note coils, and "scale tone" exercises where you play Maj/min 3rds instead of playing every note. Box positions are never covered, which was interesting to me, because that is how I initially learned.
Section two treats the F min. pentatonic the same way. Again, F because it is the first note on the fretboard for a movable position (Just like you might teach someone a bar chord in F and then say, "Hey you can move it wherever.") The exercises in this section are entirely similar to the first section except that the picking pattern is different because there are only two notes per string (per pattern). The "blues" scale variant is never mentioned.
The third section presents arpeggios of most chords in various keys. The author calls these "chord runs". Notably, he never gets to inversions, but once again he has you practicing patterns in a way that is likely to make them stick in your "muscle memory" (Which is what an "exercise book" should do, I think.)
The final section presents "chromatic exercises" which are the same "dexterity" or "speed" exercises you find in a lot of other books. They are perfectly good exercises, but their presentation here isn't especially notable. They do a good job of pushing us past the 200 page mark ;-)
All in all, it is worth the asking price, and if you learn the exercises and repeat them a lot you may actually get something out of it.
(edit 2009-01-23) In reading the rest of the reviews I notice that there are a lot of negative comments about the exercises being presented in F. All of the positions are movable, so this is a silly reason to disregard this book. Also, if you grab a copy of "Scales and Modes" all of the exercises in the first two sections of "Exercises" can easily be translated to any of the other scales. I have begun to do exactly that, and have been impressed by the speed at which the scales take to my fingers when practiced this way.