First and foremost you will have to run a power wire straight from the battery to an amp for the subs. Probably at least 4 gauge. You will have to ground the amp to the chassis, run a remote wire and RCAs from the radio to the amp. Remote wire is to tell the amp to turn on, the RCAs send the signal to the amp. That is the basic jist. If you don't feel comfortable doing it yourself you can always have a shop do it. It shouldn't cost too much. But look to spend at least $60 on a complete amp wiring kit, all be it not the best stuff but it should get you bye if your on a budget.
As far as equipment recomendations. My advice is to audition as many amps and subs you can before you buy. There will be a lot of different people recommending alot of different products, some of which you've never heard of. MOst of them are very good and cost effective. But in the end you'll need to choose something that sounds good to YOU and is within your budget.
P.S. STAY AWAY FROM AUDIOBAHN, You can thank me later
