2009 marks the 50th anniversary of Miles Davis' landmark album Kind of Blue. This album combines a new approach (for the time) to jazz with a very listenable sound that has brought it both the respect of the jazz community and immense popularity. Ashley Kahn wrote a book, published in 2000, dedicated entirely to this one record.
Kind of Blue is the classic example of modal jazz. Be-Bop and earlier forms of jazz were based on chord structures, with improvisations based on the notes in the chords and the changes. Modal jazz was based on scales.
Modal jazz remains popular today, in part because it is easier to play. It can be a place for students who haven't fully mastered their instruments to begin to get a feel for improvisation.
About the same time as Davis and his all-star band were playing cool, Ornette Coleman was developing "free jazz." This was a much rougher sound that also abandoned the Be-Bop tonal structure. The 1950's and 60's were a great period of innovation in jazz, with some of the real musical giants applying both intellect and heart to a true American art form.
The library has many books and cd's featuring jazz. Just search the catalog for jazz. You can use the "limit by" box to get only recordings or books if you'd like.