The best study material is a box or 2 in front of you running Red Hat. I read the guides, and the websites, but nothing compared to my hands on experience w/ the OS.
Take a system, and then break it in various ways. Have a friend break it for you, so you don't know quite whats wrong.
Have a friend come up w/ a requirement set for an install. Service A has to be configured like so, has to only allow lan B to connect, GUI login, this that, and other stuff (within the included RH software), then see if you can fulfill the requirements w/in 2 hours. (start your time when you touch the blank system, not after you install the OS).
I jumped straight into the RH300 course, and got my RHCE w/out problems. The class didn't help too much, mostly w/ just the borked boot loader issues. The rest was due to my hands on experience w/ Red Hat.