Just thought I'd share my diagram of wiring for car audio as an example for others that have questions... depending on the setup, most will look similar to this. Any questions, post here and I will try my best to answer them.

note that my 6-farad capacitor is attached directly to the amp (left hand side of the diagram) (both power and ground). This is because my amp has a special place for capacitors. Most amp/caps will wire like the 1-farad attached to the 600W Amp (on the right hand side of the diagram)

and this one is for car lighting (CCFL's, neon's, LED's, etc)