One of the best exercises for the aspiring jazz player is the blues format. It's 12 bars long, with a fairly standard chord structure, and easy to build up a solo with. In fact it's very good practice.
This is the chord progression we'll be using for the whole of this lesson:
G7 - C7 - G7 - G7(alt)
C7 - C#o - G7 - Bm7/E7
Am7 - D7 - G7/E7 - Am7/D7
You'll see I've 'improved' these chords with the usual jazz extensions and alterations. This is the way they're normally played.
There's an MP3 to go with this lesson The chords are slightly different but the ideas are the same:
If you've been playing for some time (this is an intermediate lesson) you'll already know the G minor pentatonic scale at the 3rd fret. I've included the b5 note (Db) in this.
You also probably know that you can use the minor pentatonic over all the chords in a blues progression. Here's a simple solo using this scale.