You'll need what you listed above, but you have to specify if you got an aftermarket head unit or not. If you're still using the stock HU, you'll need a line out converter (Audio Control makes a popular one) to provide the input signal to your amplifier.
If you go to Crutchfield's site, there are some good basic tutorials about car audio on there. Much easier than explaining all the basics on a forum.
2013 Race Red GT/CS 6MT; Elec Pkg; RAAMat on the doors; Morel Tempo 5x7 coaxials; GT500 axle-backs painted black