o.k...make sure that rom is for your device and carrier.

Before the flash, make a backup via recovery.
Do a factory reset, wipe cache, dalvik cache, then flash the rom.
Reboot.
If the instructions on the download site are different on how to flash that rom, follow those instead, but basically, that is how to flash the rom.
Also make sure you check the md5 of the download and make sure it matches what is posted on the download site. If the numbers match, then the file is intact and not corrupt.
If you need more info on how to check the md5, see this:
http://androidforums.com/faqs/443074-md5-verification.html
I've got to go for the night...if you need more help, I'll be checking in tomorrow to see how you are doing, unless someone else chimes in
If you need immediate help, hit me up with a p.m. and I'll do my best to assist
