Several years ago, a guy by the name of Larry Ross Norred served as a clinician in one of my high school bands, and during the clinic he promoted something I had never seen before or since. He had created a book with all of the possible scales, common chords, and chord substitutions he could find. It has been a tool in my compositional arsenal since I began composing. And the best part is he offers it free on his website at http://changes98.com.