I have bought mine from ebay. It was my first time too. I recommend paying using paypal as you will get paypal buyer protection along with ebay's protection.
Check the rating of the seller. Reliable sellers will have around 99% positive feedback.
I PMed you the one I bought. You can use that as an example. (Not yet allowed to post links
The model I got was a Hongkong verision. And the seller included Fedex priority upgrade and a North American charger as well as a car charger for free
Hope this helps.