Some Useful Website :
References:
Linux Forums - www.linuxforums.org [1]
RPM Repositories:
http://rpmfind.net [2] (the firs site you should visit)
http://rpm.pbone.net/ [3] (a lot of packages for many distributions)
http://dag.wieers.com/home-made/apt/ [4]
http://freshrpms.net/ [5] (a lot of packages for Fedora, Red Hat, Yellow Dog, etc)
http://rpm.livna.org/ [6] (packages for Fedora systems not included in the official releases)
Freshrpms and livna can also be used as yum repositories for distros such as Centos, Fedora...
New References will be added from time to time