These are the books that I recommend to learn more about the technologies I use. These are affiliate links to Amazon.com. If you follow these links and buy a book, I'll get a tiny bit of your purchase price.
HTML, XHTML and CSS For Dummies
It's hard to recommend a book titled For Dummies but I've loved every book I've read in the series.
HTML 5 For Dummies Quick Reference
This is the reference version of the For Dummies book.
PHP & MySQL For Dummies, 4th Edition
A fun way to learn PHP and MySQL. The language and database system I use for web development.