Randelli knows what he is talking about. I read that book and REALLY wanted to build an amp. Then I stumbled on to Randelli's project HELLFIRE
and I was hooked ! I built mine, and participated in the threads of several others that have since built one. (hint - search this forum for Hellfire to read everyone's experiences)
I'm so hooked, I'm building a second Hellfire. And looking at everything that even vaguely resembles an amp to find more projects.
But read the book - it will give you very important understanding of key concepts, as well as a healthy appreciation for safety. And it will really make you wanna do it !
As far as web reading, this Squawk Box section is about as good as it gets - read anything by Hipofutura, Twang, Lyle Caldwell, Randelli, Cygnus X1, etc. These guys are really SMART, and make incredible contributions to the community knowledge pool. Some of it actually seems to stick for me - I've learned an enormous amount here. Best of luck !