no need to rename zip.
select zip and follow the command on the menu
EDIT:
if Maderstcok remember to reboot before doing anything as far a root and rom
Ok, your advice about plugging into the wall instead of the computer was what allowed me to get to Clockwork recovery. Prior to that I was only able to get into the android recovery. So I was able to re-install Liberty, and all seems to be going well...resyncing now.
I still have a question as to whether or not installing a zip file or using an update.zip are really the same thing? i.e., if I were still only able to get into android recovery, could I rename the Liberty Rom zip to update.zip and use that option from the recovery menu? Because there is no other install from sdcard option in that menu like there is in the Clockwork recovery menu.
Thanks for the help.