It's simple guys, either follow what was posted above, or go to the link below and follow the instructions, the only thing I will add to the instructions below is after you have entered your beta number into the cmd box it will root the phone and then after it will ask if you want to install the clockwork recovery, I would say yes and then you can change to RA later if you want but at least start with that one I would suggest.
Guide to rooting Gingerbread with Revolutionary - Android Forums