If you want to learn more about AOA and spins, in addition to picking up one of those books above, go out and find a good acro instructor and go flying. Books are great but there's no substitute for experience in an airplane, that's where you will develop the 'feel' for what the airplane is telling you.
Start looking for good Acro IP's, and read some good stuff, free right here:
http://eaa.org/intheloop/issues/default.asp
Hey, with enough practice, you could even land upside down, like this:
http://www.youtube.com/watch?v=1ApSDpnA2k0