I am here to help shed some light on kegging systems! As St. Marcos hinted at, you need to have your system balanced...not adjust pressures!!!!!!!!!!!!
First, use the beer carbonation chart that Seven posted. Find your serving temperature and cross reference it with the style's carbonation recommendation and apply that pressure for a week. I force carb but do not use the 30 psi and shake method. That's a good way to overpressure your beer which takes a week to bleed off properly. If you are determined to carb faster, do the shake method at the target pressure to avoid overshooting but wait 24 hours before serving or you'll get foam.
You can carbonate at room temp using the chart, however, you'll need to chill it to serve. Make sure you apply the carbing pressure to keg while chilling since it will require more CO2 at colder pressures to achieve a proper carb level.
THERE IS NO SEPARATE SERVING PRESSURE!!!! This is the biggest myth I see propagated by "experienced" keggers to noobs! At one time I also believed this myth. However, THE PRESSURE IS ALWAYS APPLIED FOR CARBONATION!! Now there are those who say that then it pours too fast and foams....yes it does. That means you need a longer serving line. Most keg systems youbuy come with a 5 ft or shorter hose...its too short. Use an 8-10 run of beer line to compensate for at typical 13-14 psi carb at 38F. If you are curious to learn more, search for threads or google draft line balancing or visit micromatic for some good educational material.
And please continue to spread the word on proper kegging practices!!!!!
