PayPal certifies all accounts. If the person you are paying is "un-verified" don't go through with it.
They have a place where you can make complaints, and stuf like that. But for the most part PayPal is safe. Ask ther person for there home phone number nad address, and do a reverse look up to make SURE it a residential addres and real person. Also, make sure thy have alot of other positive sales, or you trust them ALOT.
NEVER take money orders, huge scam. I have succesfully received 2 mony orders in my time, no scam. But it's just not safe, ESPECIALLY international ones.
http://www.sccfcu.org/asp/services/service_6_3.asp -Google "money order scam" a million stories are available. PayPal and eBay however are pretty error free if you can buy/sell with good judgement.