As usual, I found HTMLGoodies to be a good source for CSS kind of stuff.
http://www.htmlgoodies.com/beyond/css.html It is very very useful. One thing I like, is that you can almost create your own tags, using a combination of a class in your style sheet and the <span> tag.
You might know how, but if you did this in the style sheet:
.dark {font-family: tahoma, verdana; color: 122015;}
then you could use the span tag like this: <span class="dark">this is dark text</span> to make that text look how you want.
Don't forget to use it to color your scrollbars, and for link colors and things. The best way to do cool effects is by getting the style sheets from sites you like, and seeing what they used. Also, remember you can use "../style.css" to get the style sheet from a directory up. I used to put a copy of my style sheet in every directory or have the full url to it each time.