. . . but I think the best book along those lines is, "The Science of the Craft" by William Keith. It's a really good read if you're an inquisitive type who enjoys scientific conjecture as to how magic works.
I really enjoyed Keith's book. "I don't know what it is, but I know it when I see it" - Pg. 57 (right before he defines magic). Quantum physics, power, energy . . . love it. Not the I necessarily agree with all of his conjecture. I mean, Keith jumps out on and up and down on the limb a couple times, but it is loads better than most of the other stupid shit out there. Plus, even an attempt at "science" makes my little heart go thumpity-thump.