I'm glad that I found this thread, because I was just fixing to ask that question myself. I will check out "Build Your Own Web Site the Right Way." I have been looking on amazon and at the bookstores trying to find a good book, but it seems like most of them are either oversimplified, or obsolete as far as the tags and methods.
Like Joder said, w3schools.com is one of the best sites for starting out if you are wanting to learn it online. Htmldog.com is also a good one. There is also a free 10 week xhtml class that you can sign up for from about.com's About University.