I think you mean Red Hat Enterprise Linux (RHEL), ES version... This is NOT a free download, it requires you to pay a subscription.
If you are looking for the Open Source equivalent, check out CentOS (Community Enterprise Operating System). This is RedHat Enterprise Linux stripped of all it's licensing agreements. This is NOT a spin-off...
This can be downloaded from:
If you would like to take a look at other distrobutions as well, checkout the follwing link:
You can follow the RedHat manuals verbatim, when using CentOS. CentOS actually links you to the RedHat site for their documentation, they use the same manuals.