Yep it's a big post typing by hand, so about youre question for CMS in youre site.
Moset popularity and flexibility it's PHP Nuke http://www.phpnuke.org/
By this project you may manage youre content non knowing PHP
In PHP Nuke you may find anything, pool system, csm, user management, e.t.c by the way it's too recommend to see:
http://www.hotscripts.com/PHP/Scripts_a ... l_Systems/
You find many more CSM and may try it.
Good Luck! :^)