As mentioned above, Fedora is a test bed for future options in RH. Not all of the software will make it into a release of RHEL, and a cutting edge distro does run the chance of something going wrong during a standard system update.
As you are looking to get into the Admin game, CentOS would be the best choice. It's a system that is tried and tested, and is already capable of running on a corporate server with high marks on stability.
Centos is a rebuild (minus branding and Red Hat Network and paid for support) of the actual operating system that seems to be most commonly used in server rooms.
Originally Posted by Dexinthecity
As for resources... LinuxCommand.org: Learn the Linux command line. Write shell scripts. and http://rute.2038bug.com/index.html.gz should take you all the way from a beginner to doing some fairly advanced stuff.
Don't worry about questions as a friend of mine puts it "If you don't know and you don't ask then you still won't know"