Check this out... You should be able to find all of the answers that you are looking for.
Browse through the stickies at the top (darker blue text), and if that doesn't answer anything, then keep looking through the existing posts, and/or search.
These guys are a little harsh on you if you were to put up this same post there. They'll just say something rude like "JUST SEARCH noob". Just letting you know... It's partially because these questions have been asked over and over, and there is a TON of excellent info about our 3Gen Eclipse's Audio. You just have to find it. It's a bit more complex than your average set-up, but once you get the concept, and learn the basic components, it'll be just as easy as any other!
Good luck! :57:
http://www.club3g.com/forum/car-audio-electronics/