Howtoforge posted a tutorial about installing Apache2 with PHP5 and MySQL support on CentOS 5.5 (LAMP)
LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on a CentOS 5.5 server with PHP5 support (mod_php) and MySQL support.Installing Apache2 With PHP5 And MySQL Support On CentOS 5.5 (LAMP)