Once you get the hang of codeing with CSS “Zen Garden” is one of the most informative sites for picking up more CSS tips.
“A demonstration of what can be accomplished visually through CSS-based design. Select any style sheet from the list to load it into this page.”
You can view lots of different web page designs all using the same html file. Each one has a different look and feel and you can view the CSS behind the design. What a fantastic way to get to know CSS, find new and better ways to code.