Try Myn's ROM in my sig. It is sense based so it will be familiar and there are TONS of peope running that ROM, so you can find a lot of information on these forums. I'm not saying it is the end all, be all for ROMs, but it is a good place to start for the reasons I noted.
As for HOW to do it? I would read over Matlock's thread a couple of times. That will be the best single source of information. It is the "Rooting for dummies" thread stickied at the top.
In short, though, you usually need to wipe data when changing to different ROMs, so you will lose your contacts. BUT, if you use Titanium Backup, you can save all of your contacts, apps, settings, etc. and restore them all after flashing a ROM. Buy the pro version for batch operations and you will save yourself some time and boredom.
