Sup guys and gals, I'm soon to buy a new car and the first thing I want to do to it is upgrade the audio on it. Now I'm looking at buying a cd player (preferably Alpine as my mate has one and its mad), and 2 12" subwoofers about, maybe speakers depending on how bad or good the stock ones are.

The thing is I don't know where to start - there's things like amplifiers and shit which I don't know what are used for, so I was wondering what do I have to do to get basically my subs working perfectly along with the cd player, and how much would installation cost?
Cheers.