Wiring diagrams

Hey I'm looking for a wiring diagram to installed a cd player in my 2000 jetta tdi, its just a tape player/radio right now with the option to put a cd changer on it. I also wanted to keep the factory amp going. Plus I making some custom fibreglass boxes to fit where the cd changer goes and on the other side where the cargo net goes. I just don't know how to wiring it up without spending a lot of time. if anyone is interested in pics of the sub box set-up let me know I should be done fibreglassing in a week. thanks guys!