For the Mac do-it-yourselfer, the web site iFixit is a great resource:
We now have manuals for 91 Mac models, 34 iPods, and a couple of iPhones. Together, our media servers currently host 154,556 images (including revision history and thumbnails) and over 1,000 step-by-step guides.
And now a bombshell for do-it-yourself repair folks from iFixit:
Today, we are giving all that content to the world. Effective immediately, we are licensing all iFixit repair manuals under the Creative Commons BY-NC-SA license. To my knowledge, this is the largest free release of repair documentation ever. We are committing to make our repair manuals available to everyone in the world, forever, for free.
That’s a strange business model, but thanks.