My typical procedure:

1. Ferment the beer for two weeks in the primary and then keg it.  No priming.  
2. Add dry hops to the keg.  The hops are usually whole hops, but I have used pellets.  The hops are in a bag with a teflon or stainless steel weight to keep them immersed.  Most, but not all, of my beers are dry hopped.
3. Pressurize the keg with CO2 to 10 psi to set the seal.    Cycle the pressure two or three times to purge the air.  Remove the CO2 source and substitute a pressure gauge on the keg gas connect to monitor the pressure.
4. Keep the keg at fermentation temperature.  The pressure will gradually drop over the course of 1- 3 days, typically to 4 – 6 psi, and then begin to rise.   Beers without dry hops may take a week or more.   When the pressure exceeds 20 – 25 psi, release it slowly to keep it from over pressurizing and to allow fermentation to continue.
5. After a few weeks when the pressure is stable, the keg is ready for chilling to serving temperature.

My “six keg keezer” has pressure gauges for each keg.  Each keg is normally pressure isolated from the others, but there is a cross connect system to add external CO2 or transfer pressure between kegs. If the pressure in one keg is low, there is usually another that is a bit high, so it can be balanced internally and external CO2 additions are infrequent.  I once went over 10 years using the same 5 pound CO2 cylinder.

- Woody