Just finished a talk at the Wisconsin Midrange Computer Professional Association and wanted to share the info. This particular talk was an introduction to PHP.
The slides can be downloaded Here.
Check out PHP.net for all your information.
I like to search function names by adding them after the .net of the PHP url… so do search strlen(), you can do php.net/strlen
More PHP Tutorials
Check out w3schools PHP tutorials (sadly, the page is ASP though!)