CentOS-Asterisk-FreePBX install and configure guide for CentOSv5.x, Asteriskv1.6.x, and FreePBX v2.4.x.  Includes every detail in the form of step by step instructions from bare metal to a running VoIP PBX in about 2 hours.  This is not a production install guide since Asterisk 1.6 is still beta.

I have also tested this with FreePBX v2.5.0alpha1.

For printer friendly version of this guide create an account and login.  It will only take a few minutes.