If your PC has onboard SATA, it might be compatible. If not, you will need the VIA SATA card with the 6421 chipset. If you drive is a Lite-ON, you will also need a key-reader. Example CK3 Probe, Maximus Spear, homemade probe.
take the faceplate off your xbox and theres gonna be a hole on the right side of the dvd drive take a flashlight and look yella wires - liteon white wires - benq before this check the disc tray
Take the faceplate of your xbox, look through the little hole, if you see a yellow wire you have a lite on
If you have a liteon then there is a great tut in the sticky for making the spear. If you need any help PM me your email address (don't post in the forum) and I will provide info for the drive you have.
You can also buy a connectivity kit, so you don't have to have your drive hooked up to your 360 when flashing.