yeah be sure to read the stickied threads about flashing roms first, its a breeze once you unlock your phone. and everyone here is super supportive for any questions u may have, but you cant install a rom without flashing your phone cuz installing a new rom is flashing it. unlock your phone here:
http://forum.ppcgeeks.com/showthread.php?t=42503 first if you want to flash a new rom. just be sure the rom is CDMA and not GSM if ur on sprint