Jeff Atwood has collected some good quotes, including one from DevDiv's own
Mike Pope, about the importance of documentation. Also many good comments that have additional interesting points. I particularly enjoy the excellent rant about hardware documentation that includes pages and pages about connecting the cables, but nothing about anything you'd need help on. I wonder how much of our API documentation falls into the same trap: document in great detail the things most people will already know, and skimp on the hard stuff because, really, we don't know how it really works until it's too late to document it.