leak detection pump - evap emmisions

Hi, My car is a 1998 jetta gt 2.0 8v. I'm trying to troubleshoot a code p0442 which is a small leak in the evaporative emmisions control system. For starters, where is the leak detection pump located? I've already installed a new gas cap but where else should I look for problems? What other components are in the system? Charcoal canister, regulator valve?? right?
Thanks

You're looking at the right parts (I can't say I know of a vacuum pump for that system though), small leaks can be very hard to find. Most shops use a smoke machine to help find those leaks.