Redhat 5 Tweaking steps:

http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch14_:_Linux_Firewalls_Using_iptables

http://www.thegeekstuff.com/2009/06/how-to-disable-selinux-redhat-fedora-debian-unix/

http://www.cyberciti.biz/faq/disable-linux-firewall-under-centos-rhel-fedora/

http://www.servepath.com/support/redhat-securitychecklist.php

http://linuxhelp.blogspot.com/2006/04/enabling-and-disabling-services-during_01.html#axzz0f2M0zEs0