Update: Thanks again for your help. I just kegged my first home brew. I had some trouble getting the lid to seal, so I went back and hit the keg with 30 psi and it sealed up fine. (Next time I'll try keg lube and putting dimes under the legs, etc.) I dialed it down to 15 psi as I'm going to store it for 3 more weeks. It's in the fridge now at 35 degrees.
Questions: Once the beer is fully carbonated, can I detach the CO2 tank and then use it again when I'm ready to dispense beer? And - how do I make sure that I don't over-carbonate the beer?