You're best off picking a model and finding out the forums and pages about it. The intricacies of each model (and often year) are not very translatable.
'Course, since you asked about "general" there's a stickie at the top with info about bikes. If you want specifics about mechanical stuff, I'd just Google them or use the bike-specific sites.
Manuals, however, are indispensible.
Dragging knee is for the track, and dragging tail is for the lot. --Kane Friesen
When you're in a car, you're watching a movie; when you're on a bike, you're in the movie. --Robert Pirsig
Identity theft is not Fun