I would jump onto some car audio specific forums and more importantly, jump on YouTube and start watching installation videos.
At the very least, you are going to need to identify your car's head unit and see if you have RCA audio preouts for a subwoofer, or if you will need to do something else there. Likewise, you will need to connect to the car's battery.
This isn't something that those comfortable with a wrench or who want to get comfortable with a wrench can't do, but it is also not for the faint of heart.
Writing up a complete list of how to do this yourself isn't something you are as likely to get here. But, I am sure YouTube has video after video after video of how to install an amplifier into a car and to do the wiring and everything else along with all the tools and such that you will need.
I would probably start my forum questions over at Crutchfield or at least on some more car audio specific forums.
