You'll want to get an amp wiring kit (size depending on the size of your amp). The wires you'll need are: power/ground wire, remote wire, RCAs, and speaker wire. The power wire is run from your battery to the amp. The ground wire is attached to the metal frame of the vehicle somewhere near the amp. The remote wire is run from the head unit to the amp to give the amp a "turn on" signal. The RCAs are run from the head unit to the amp to provide the sound signals. The speaker wires are run from the amp to the subs.

Contrary to popular belief, you do not need a "Rockford Fosgate" wiring kit from Best Buy. You can obtain a good wiring kit made by Scosche from WalMart and it will perform just as well as the RF kit for half the price.

Also, if you have a factory deck, the device you'll need to run RCAs to the amp is called a line output converter.

Here's a link to a tutorial for installing your amp: http://www.mmxpress.com/technical/ampinstall.htm