Accessory power outlet

Evening folks,
One of the upgrades I have planned to do is to add a couple of accessory power outlets, for Ipod, GPS or whatever. I plan to hit a local junkyard and try to get a couple on the cheap.
How do they get wired in? Should I try and get more than just the outlet from the dash when I go the junkyard? My Dakota has one with a neat cap that says 12V 20Amp, a couple of those would look pretty good IMHO.
Thanks,
C
Author: admin