CSS Book
Create visually rich, accessible, and efficient web pages. the book covers most of what comprises the initial level of css, or css1 (cascading style sheets, level 1), along with several key features of css2 (cascading style sheets, level 2) supported by current browsers. additional information is also included on using css with xhtml and xml, javascript, and dynamic html.
http://www.callihan.com/cssbook/
Blooberry
Blooberry
http://www.blooberry.com/indexdot/css/index.html
Free Webmastertools
Learn about css using these tutorials with copy and paste examples.
http://www.freewebmastertips.com/tutorials/css/
HTMLgoodies - CSS Tutorial
HTMLgoodies - CSS Tutorial
http://htmlgoodies.earthweb.com/beyond/css.html
Sitepoint CSS tutorials
Sitepoint.com - with a vast variety of web design tutorials and articles coupled with a vibrant and well informed community, sitepoint the natural place to go to grow your online business
http://www.sitepoint.com/subcat/css
Site Experts - intro CSS
Interactive tour of css - introduction
http://www.siteexperts.com/css/intro.asp
W3C Tutorial
W3c's overview of web style sheets: css.
http://www.w3.org/style/css/