W3C - Cascading Style Sheets -  .

Cascading Style Sheets: Celebrating 10 Years with Style - - W3C mini-site to mark the 10-year anniversary of the first published CSS recommendation. Includes time-line, hall of fame, essays, and a gallery.

Code Style - CSS Style Guide - - Includes a cross-platform font sampler, information on media stylesheets, FAQ, and a glossary.

CSS Naked Day - - On April 5th, simply remove all CSS from your website, stripping it entirely of its design. Promoting web standards, plain and simple.

css-discuss Mailing List - - Practical discussions of CSS and its use. High volume list.

CSS3.info - - Newest developments in CSS based webdesign.

Dive into Mark: CSS - - Archive of postings to Mark Pilgrim's weblog.

Eric Meyer - CSS - - Articles, tutorials, discussion and resources for CSS.

EServer TC Library: Cascading Style Sheets - - A collection of dozens of rated, reviewed online resources for developers who work with cascading style sheets in web and information design.

Web Developer's Virtual Library - Cascading Style Sheets - - Teaches how to use CSS to improve the look and structure of HTML pages. Links discuss how to use CSS to avoid table layouts, colors, fonts, and layers.

WebmasterWorld: CSS Forum - - Discussions on layout, compatibility and trouble shooting.