Anybody's Bike Book is probably the best general-purpose
bicycle repair book you'll find. It's not a source of definitive answers for specific bike models, but an accessible volume explaining just about every problem that can occur with a bike, and detailed procedures to fix them.
Written by Tom Cuthbertson and illustrated by Rick Morrall, the book has been through several editions and, according to the cover of the copy I have in front of me (Ten Speed Press, 1998, ISBN 0-89815-996-2) has "over 1 million copies in print." It covers all ordinary bicycle types - road bikes, mountain bikes, cruisers, and hybrids - but not fancy, custom models or the highly specialized racing bikes that competitive riders use. I've got a bike that doesn't fit exactly into any of those categories - it's a mutant aluminum-frame cruiser with a six-speed grip gear shift - but still didn't have any trouble finding the relevant sections for all my bicycle's parts.
Cuthbertson's style is very informal and colloquial (a lot like dannye, come to think of it), but still comprehensive and unambiguous. Morrall's illustrations are whimsical without detracting from their instructiveness. Both "proper" repairs and emergency field improvisations receive ample coverage, so it'd be a good idea to take the book along on long rides far from civilization. Organization is excellent - a reader can find information dealing with the problem at hand within seconds. If Chilton made auto repair manuals like this, I suspect a lot more people would be fixing their own cars!
Anybody's Bike Book would be a worthwhile investment for just about any bicyclist with greater mechanical aptitude than a sea slug. Read the book, use your brain, and you will be able to fix your bike. And it's written well enough to be read casually without inducing narcolepsy.