The php website is located at
http://www.php.net/
PHP initially stood for personal home page, but it was later called PHP Hypertext Preprocessor or php for short.
This site is an example of a site which uses php, notice the .php extension in the address bar.
There are quite a lot of off the shelf php scripts located here
http://php.resourceindex.com/Complete_Scripts/
You could use frontpage in addition to an off the shelf php script if you are not familiar with web programming.