I have the Modes for Guitar book, but I haven't worked through it yet. I did read through some of it and it looks great, particularly the way he writes these great little descriptions of each mode.

Two books I am working through are:

The Guitar Fretboard Workbook
http://www.amazon.com/Guitar-Fretboard-Workbook-Barrett-Tagliarino/dp/0634049011/ref=sr_1_1?s=books&ie=UTF8&qid=1362436494&sr=1-1&keywords=guitar+fretboard+workbook

and Guitar Soloing
http://www.amazon.com/Guitar-Soloing-Contemporary-Improvisation-Included/dp/0793581869/ref=sr_1_2?s=books&ie=UTF8&qid=1362436654&sr=1-2&keywords=guitar+soloing

Both are great, but require dedication to through.. Guitar Soloing really opened my eyes to working with seven note scales and broke me out of my pentatonic minor rut. The Guitar Fretboard Workbook is a must have for just about anyone wanting to learn scales. Memorizing scale patterns by writing them out on paper first, before you try to play them, sure speeds up the learning process.