For more design tips from Robin Williams, check out The Non-Designer's Web Book (with John Tollett), The Non-Designer's Design Book, The Non-Designer's Type Book, and The Non-Designer's Scan and Print Book (with coauthor Sandee Cohen), all published by Peachpit Press and found at quality bookstores everywhere.
If you are specifying the text to appear in a certain typeface (if you're not, ignore this), typically Helvetica or Arial and Times or Times Roman, please specify Geneva in front of Helvetica, and New York in front of Times. This will make the text on Macintoshes appear much so much cleaner and easier to read. (If you use a Mac, set your default font to New York instead of Times, and you will be amazed at how much easier it is to read web pages. Change it back to Times before you print a page.)