Now, you know the basics of style sheet construction. The rest is just a matter of plugging properties and values into the appropriate slots. You'll find a nifty list of those right here. Please note that the properties marked "CSS2" may not work with all browsers.
For a little bit of practice, though, why not try writing a style sheet yourself? Your mission, should you choose to accept it, is to create an inline style which causes all text enclosed in paragraph tags to show up as red 10-point Arial. (Give sans-serif as the alternative.) If you're feeling really adventurous, also make it so that all text enclosed in <STRONG> tags shows up as bold, 14-point Times New Roman, giving Times as the alternate font. Not sure how to make it bold? Check the "Text Properties" section of the chart and look under "font-weight."
If you just can't seem to make it work, try taking a peek at this code for the solution to the above exercise.
Don't be afraid to experiment, and don't be afraid to make mistakes. With a little trial, error and patience, soon you'll be a CSS veteran.