I just bought a Seagate Barracuda 7200.10 ST3320620AS Hard Drive - OEM and I was wondering what kinda cable would I need to connect it to everything else...
You need a Sata cable and a Sata power connector. If you don't have any Sata power connectors coming out of your PSU you can buy a molex to Sata adapter.
sata cable
Molex to sata adapter, white end Molex, black end sata
Look around, if you need both Tiger Direct has both of them together for $6.99