The best way is to install it on a test box and play with it. Blow it up and fix it. Get a couple good books and take a look at the mountains of Linux support websites online. Join the Red Hat Linux mailing list at:
http://www.redhat.com/support/forums/
You may also want to get the "Under the Brim" Red Hat newsletter.
There's a good book called Master RedHat Linux Visually that comes with the OS on CD. It has step by step instructions with screen shots and covers both Command Line and GUI proceedures. I had a Linux server up and running in no time...
It's even pretty reasonably priced $24.95 on Amazon. The only snag is its version 6.2
Another book that is very good is The Red Hat Linux 7.2 Bible. This one is somewhat more technical in its approach, but will offer more "longevity"...and of course it comes with a newer version of the OS.
The Dummies book is only fair...very rudimentary and it was a bit of a disappointment to me.
I do like my O'Reilly Linux book, but it took me getting comfortable with the Visually book before I really got much out of it.
oh, and by far my favorite Linux website is:
http://www.xmission.com/~dmacleod/unix/linux/contents.ht ml
(remove any spaces in the URL)
Hopethis helps!