Thanks guys, and I'll look into that book, it sounds interesting.
Probably the best (and most usefull so far) thing that I learned was learning Maj7, Min7, and Dom7 chords and all their inversions up the neck. I like melodic chord progressions a lot, and its definately made studying jazz a lot easier.
The second inversion of a Maj7 with its bass note on the 6th string is a handfull:
Dmaj7/A
e:x
B:3
G:6
D:4
A:x
E:5
I like playing it and asking other musicians what they thought it was. It puts the 1st and the 7th degrees right next to eachother, and the semi-tone relationship sounds really dissonant. "Ew! That must have been some nasty diminished chord, right?", "Erm, no, just a major chord, sorry!"