Definitely use the original cable and plug it came with to recharge initially. I just bought 3 new "OEM" cables off eBay and within a couple of days, one has completely stopped working and the other two have melted at the ends (end that plugs into the phone itself) just from leaving it connected to the plug (wall plug) and connected to my USB (computer I sync with).
Wrote the dude on eBay and sure enough, he sent me 3 more "OEM" cables and they feel equally as cheap. Never had this problem with any of the non-OEM cables bought off eBay for my iPhone 4S. But I'd rather spend a few extra bucks to make sure I'm not frying my iPhone.