Cascading Style Sheets: making the web work

Books on Website Development and CSS

CSS Zen Garden: The Beauty in CSS Design The Zen Garden is a fantastic resource for anyone interested in the use of CSS.
A List Apart
css/edge Eric A. Meyer is famous for books on accessibly and use of CSS.
www.positioniseverything.net Help you position your elements using CSS.
CSSBeauty Learn by example.
CSS Vault :: Another great site to explore for inspiration. It also has links to articles about CSS design.
Listamatic How to style lists.
CSS Specification The official documentation at the W3C.
CSS Discuss The css-discuss Wiki