First of all, I’m going to assume you already have httpd and php installed. If you don’t have them already you should install them now. I recommend Jason Litka’s Yum Repository.
This guide is written with bash comments, so the whole text block below can be copied and pasted into an install.sh file if you’d rather not go through step by step. I wouldn’t recommend it though, as something could always go wrong, and it would be rather challenging hunting down the problem in that massive wall of output lines!