Check out the Jamey Aebersold Jazz Handbook - you can download it for free in .pdf here:
http://www.jazzbooks.com/mm5/merchant.mvc?Screen=FQBK&Store_Code=JAJAZZ
Some more very helpful info here:
http://www.jazzbooks.com/mm5/merchant.mvc?Screen=FREE&Store_Code=JAJAZZ
http://www.jazzbooks.com/mm5/merchant.mvc?Screen=FQBK&Store_Code=JAJAZZ
Some more very helpful info here:
http://www.jazzbooks.com/mm5/merchant.mvc?Screen=FREE&Store_Code=JAJAZZ