Microsoft Expression Web For Dummies

W3schools has beginning, step-by-step online tutorials for the complete novice to HTML and CSS.

http://www.w3schools.com

This excellent online CSS tutorial gets you up to speed on all aspects of CSS:

http://www.westciv.com/style_master/academy/css_tutorial

At the following site, you can find tutorials for various aspects of CSS design, such as floating page elements, creating navigation bar lists, and understanding selectors:

http://www.css.maxdesign.com.au

Webmonkey has how-to guides, articles, and reference material. It's a good general Web resource:

http://www.webmonkey.com