Can someone help me with a car audio set up?
 

I need a total audio overhaul in my car. I'm completely new to this, but am willing to drop a good amount of cash. I just don't want to get an amp that can't handle 2 12"s or anything like that. I have a 2011 Mazda 3, which has 5 1/4" size speakers in it. I don't know how much power my amp needs to run the subs or anything, so any advice you guys have is appreciated.