One of the things you want to do first before you start tweaking your phone is to make sure you have insurance. After that then you can unlock your phone here is the link. This is if you're using sprint.
http://forum.ppcgeeks.com/showthread.php?t=42503
Once you have it unlock than you can start playing around and searching which ROM's you like.
I'm currently using Mighty ROM 5 and is pretty good on battery. In the Stock ROM which is the software the phone comes with, the battery life is really bad.