Re: good book on amps
Gerald Weber puts out some great stuff. Some of it is very technical, though. Aspen Pittman's book (Tube AmpBook) is good too, but also technical. There's a book on guitar/amp maintenance for guitar players, by Richie Fliegler. I think it's called Complete Guitar & Amp Maintenance. Look on the JK Luthier website, they have it for $14.95. It's one of those books I've been meaning to get for a while.
Good luck,
Jeff