htmldog isn't that bad, but all you'll really need to know about CSS is @ http://www.w3.org/TR/REC-CSS2/
Whoa, Gary, long time no see! I began to get a basis with the Ian Lloyd book Build Your Web Site the Right Way Using HTML and CSS, and got a better idea of various layouts from HTML Utopia: Designing Without Tables by Rachel Andrew and Dan Shafer. The rest I've learned here, or at the other Point, or at various places like WaSP, htmldog, Mike Cherim's experiments and Eric Meyers, as well as that CSS Zen Garden book... so many juicy tricks!