Not quite sure what you are asking..."which pin goes into the power supply"
1. Make sure all your pedals use the same pin configuration as your power supply - they can be either center + or center - (the hole)...other than that, it doesn't matter which end of a cable goes where, as long as the above is compatible.
2. Don't over load the power supply - find out what your pedals each draw, in milliamperes, and see what the PS is rated for, total amps. Just add up the pedals' amps = total amps.