Just using the out of the box RedHat packages you will realize soon that there are a lot of applications that you are missing. The solution is to install other repositories that yum can use to get the software that you are trying to install. One such repository is the “RPMForge” (http://wiki.centos.org/AdditionalResources/Repositories/RPMForge), this repository has many more software so you will not have to keep chasing software and compile them if you do not have the time .
I also like to use the atomicop repos http://3es.atomicrocketturtle.com/packages/atomic-release/ just run the “RPM” and it will take care of installing the repos.
References:
Additional Repositories
http://wiki.centos.org/AdditionalResources/Repositories/RPMForge
DAG
http://dag.wieers.com/rpm/FAQ.php#B
RPMforge
http://rpmrepo.org/RPMforge