In my search for information on PHP I stumbled upon phpclasses.org. You have to register but it is free for the general content. The site contains classes on everything from database wrappers to xml parsers. You can sign up for the newsletter and be notified of new submissions and updates to the site which makes it easy to track and might even pop some ideas into your head that you had not thought about. Check it out when you get a chance, I think you will enjoy it.