(Languages: be bg de el en es id ja kk mo nl pl ro-1 ro-2 ru tl tr tt uk)
(This page uses CSS style sheets)
For beginners, Starting with HTML + CSS teaches how to create a style sheet. For a quick introduction to CSS, try chapter 2 of Lie & Bos or Dave Raggett's intro to CSS. Or see examples of styling XML and CSS tips & tricks.
Some non-English resources:
English resources:
A selection of books on CSS (in no particular order). Note that I have not read most of them.
Mailing lists and Usenet News groups.
Resources that catalogue links to other resources. (Which makes this list a tertiary resource… )
The slides of all (public) presentations given by W3C staff can be found on the W3C Talks page.