I just discovered a great educational resource for jazz musicians–I am surprised that I haven’t seen this site before. PlayJazzNow.com distributes play-along MP3 files for jazz practicing. They have tracks for drummers, bassists, vocalists, horn players, pianists, and vibraphonists. Here is the page for bass materials, and here is a example of the ii-V-I sequence chart.
The most effective way to become a fluent jazz musician is to get some face time with other musicians. Play-alongs simulate this experience and allow musicians the opportunity to work on certain tunes, chord sequences and patterns by themselves. This sort of work is necessary to really develop jazz chops, and it is the sort of work that would be very difficult (excruciatingly painful for your other band mates) to do with other musicians. Working with play- alongs allows a developing (and expert) jazz musician infinite repetitions on a given sequence. Having developed fluidity and jazz language chops with the play-along tracks enables the musician to open up, experiment, and communicate once he or she gets into a live situation, rather than honking out lame lines.