Particletree has a nice post called The Underbelly of a Web App where he talks about things that need to go on behind the scenes. As someone who has worked in support for many years, I can’t stress some enough:

You can have the best people in your support team but if they can’t get the information they need. I have to deal with quite a few interfaces where I’m not completely sure the information I’m getting is complete, useful or accurate. With a single application it’s a little easier then having linked SIS and other systems but it would be nice if a single support system was in place. If your building something that you may need to support or administer in the future, keep this in mind.

Carsonified has a post on this as well

The ability to see or track stats is nice. If nothing else, the ability to export stat information would be useful. A lot of the systems I deal with don’t give much useful information so it’s difficult to tell who exactly we’re serving, how we’re doing, etc. We keep external stats right now to make up for this but it would be much more time and money savings if the systems did it themselves.

Not sure a giant book, but context and inline help. As he says, ideally it results in zero support tickets or the ones that really really need help. Quite a few problems can be fixed with better directions on the screen or better error screens to help recovery.

If you haven’t already give Defensive Design for the Web a read.