Interested in screen sharing via other approaches too, like iChat and Skype, or from your iPhone? Check out Take Control of Screen Sharing in Snow Leopard.
Read this book to learn the answers to questions like:
What can I do with remote file sharing and screen sharing?
How do I configure a Linksys router for Back to My Mac?
What smoke and mirrors does Apple use to make Back to My Mac work?
Help! I'm double-NATted, and it's really bugging me! What should I do?
How do I erase all traces of my Back to My Mac info from a public computer?
How do I use Back to My Mac to access files on a drive attached to my AirPort Extreme base station or Time Capsule?
Glenn Fleishman is a technology journalist based in Seattle, where he lives with his wife and two sons, both of whom are adept at accidentally pressing the Power button on his laptop. He's a contributing editor at TidBITS, responsible for much of their Web and publishing infrastructure; a columnist for the Seattle Times on all things Mac related; and a regular contributor to the Economist, Macworld, and Ars Technica. He appears regularly on his local public radio station, KUOW.