Strictly CSS

Dive Into Accessibility answers two questions. The first question is "Why should I make my web site more accessible?" If you do not have a web site, this book is not for you. The second question is "How can I make my web site more accessible?" If you are not convinced by the first answer, you will not be interested in the second.

Dive Into Accessibility is a really good, 30 day/step guide to building a more accessible Web site.