Assuming that your computer (the actual box that contains the hd, cpu, memory, etc) is all in one case then you will need the following:
USB extension cables for your USB peripherals,
VGA extension cable for the screen
14 ga. wires (red, yellow, black) for power connections to the PC
You will also need to fabricate some power wires for the monitor if you plan to run that from the PC power supply.
Audio cables with mini-jack to RCA type connectors
Heavier ga. power wires if you want to install an amp, etc....