04 Silverado Stereo Help

Hey guys i have a 2004 Silverado with the Bose speakers and i want to add an amp and subs but i keep the factory radio so i was told to get a JL Audio clean sweep and i have to wire it into the factory wiring but i dont know which wires are which so if anyone has a diagram or can list what each wire is that would be greatly appreciated.
thanks
-Nate