buy a nice high level converter (converts speaker output from head unit to an amp friendly rca output) the good ones will use the audio signal to turn the amp on as well. the high level adaptor will come with the wiring instructions (i use wires brand at work) and an amp wiring kit will show u how to generically hook up an amp. you could also choose an amp with high level in, but you will need to find a switched power to trigger the amp on. heres a link to your basic wiring info http://i242.photobucket.com/albums/f.../IMAGE0020.jpg
but you are on your own for wire colors for the speakers. i usually use opposite corners for speaker signal, so that front rear fade and left right balance has no effect on the sub. an amp with a remote gain control is also a great idea.