This site, along with the resources it provides, can suffice as an excellent starting point for learning CSS. By right clicking this page, and clicking View Source, you can see all of the CSS and HTML that drives this page. Although the CSS/HTML of this page is written by hand, the Javascript Menu (follow the Buy Now! link for more info) is from OpenCube. The beautiful backgrounds are provided by Abduzeedo. More information on the both of them can be found below:
http://www.opencube.com
http://www.abduzeedo.com
http://www.abduzeedo.com
The source of this webpage can also provide you with the techniques for centering a container on the page, handling opacity and transparency, switching CSS sheets with PHP/JavaScript, and provides a basic 1 column fixed-width setup to edit and tinker with.
