1) format an 8GB USB drive
2) From RHN, go to the channel you want to use - in my case RHEL6 Workstation, and choose your arch
3) Download both the minimal/network install ISO, and the full package DVD ISO - you will need both
4) Using the Fedora Live USB Creator, make the USB drive bootable using the minimal/network install ISO - be sure to leave plenty of space for the full package DVD ISO
5) once the USB drive is complete, copy the DVD ISO to the USB thumb drive - then eject the thumb drive
6) Plug the USB drive into your computer and reboot
7) You may have to hit F-12 or some other function key to get to the BIOS boot menu - select the USB device
8) You should then see the RHEL install screen - select your install option
9) Go through the install screens - you will eventually get to a screen that says something like
Choose "Hard Drive" - if it prompts you for the path, just hit Enter or "/" if you must enter something - this is the location of the DVD ISO
Q: Why is this necessary? Why can't I just create the live usb from the DVD ISO, boot from that, and install from that?
A: If you select to install from a Hard Drive, the RHEL installer program must have an ISO file to install from - it doesn't understand that you are booting from the Hard Drive that has the packages too.
I suppose you could use the DVD ISO to create the live usb, but you would also need to have the entire ISO as well.