http://www.amazon.com/Learning-MySQL-JavaScript-Step-Step/dp...
http://www.amazon.com/PHP-MySQL-Web-Development-4th/dp/06723...
Don't buy both, too much overlap. Just pick the one you like. The latter is long, but worth it. I've got more recommendations if you're interested.
This is "the" php book that everybody uses to learn php and mysql. It's also the book I used years ago. It covers both php and mysql, which is good because both are consistently used together.