The head unit wont be able to power a sub mate, you need an amp. Some sub boxes come with a built in amp so it's plug and play.
Wiring is pretty simple, there are hundreds of 'How to's' on the net and I'm sure people on here would help. It's just a matter of running an AUX cable and remote cable from the head unit, under the carpet to the boot and a power cable from the engine bay to the boot. You can earth the amp in the boot.
That's it really