I taught myself html years ago, a good resource is http://www.webmonkey.com
(surprised no one's mentioned that) They even have an HTML cheatsheet that's a good quick reference.
Now I make sites using flash and some html, (mostly flash though) and I'm working on integrating a shopping cart into my business site. (A really good one is http://www.bigcartel.com) its free and super easy. yay!