start with some basics like whats your budget
I'm not yet 100% sure that I'm going to buy, but no more than $300 for now.
You can buy a 60ghz BFL for now, around that price or lower. Its very newbie friendly, like a plug and play.
Theres people who are selling for lower then $200 or around that price.
Whatever you do though, use escrow if you plan on buying anything on this site.