Craig Fraedrich Music An excellent resource for jazz theory materials.
Mike Tomaro Mike is the author of Instrumental Arranging: A Comprehensive and Practical Guide which is an excellent book to study after completing Arranging for the Small Jazz Ensemble.
Pete Thomas Resource material for jazz theory and jazz arranging concepts.
Mark Levine Mark Levine is the author of The Jazz Theory Book published by Sher Music Co.
National Jazz Workshop "Free Stuff" Page This page is full of jazz theory and improvisation tools.