So today I found a bunch of great stuff for jazz improvisation practice. If you really want to get serious.... First of all, Band in a Box is the standard for learning to play over the changes of any tune. I use it to create playalong tracks for my bands for any solos that they have. There is no substitute when it comes to developing your ear, you just have to hear the changes over and over.
It's normally $129 at pgmusic but you can get it a lot cheaper at Kelly's Music. Academic price is only $89!! You just need the basics... It's a little pricey, but it's all you'll need-yes, Aebersolds and Hal Leonards are good for play-a-longs, but you can do all that and a lot more with this program. You can then fine massive amounts of standard tunes and extra styles on line, from other users like This Site and This Site
So it's great to have tunes to play over and a way you can plug in your own changes to work on (ii-V7-Is) or other groups of chords, but did you know that you don't have to play a new scale for each chord change? Most turn arounds and chord progressions actually have one scale in common (ex. ii-V7-I) and others (blues). I just found this great program for $20 that lets you plug in Band-in-a-Box files and analyzes the whole tune so that you have fewer scales to think about. You can check out the demo before you buy it. While at first it seems a little confusing, it really does a great analysis and makes the process simpler. This is one of those things that the pros and people with good ears do automatically, but it's really cool to figure this out sooner rather than later. Check out this site!!! It has a ton of other stuff too.....
Jazz Scale Suggester System (JSSS)