I posted in the other thread you made, but here goes, a little more detailed.
Since you ran revolutionary and it gave you S-OFF, you're now done with revolutionary. When you ran it, it installed a custom recovery. Recovery is used to flash updates to your phone. So you need to make sure that you downloaded the superuser zip file and put it on your phone's SD card. Now power down your phone. Wait a few seconds and press the volume down button and then at the same time press the power button and hold it until the white screen appears. Select recovery.
There should be an option in recovery to flash a zip from your sd card. Scroll through the menu until you find the superuser zip file and flash it. If you have a lot of stuff on your sd card, just keep scrolling down your list until it goes to the 2nd page and you'll find it. If you put it in a folder of some kind, just scroll to that folder. Anyway, once you flash the zip file, you can back out to the main menu in recovery and select "reboot". you're done.