Well, welcome to the rabbit hole. We're here for you, but you knew that.Well this is what happened. Today I bought from lhbs a used, refurbished and pressure tested 5 gallon ball lock Corny keg, a 5 pound (filled) CO2 tank, a dual guage regulator, a gas line assembly and a picnic tap assembly. Picked up from lhbs this afternoon. The guy at the shop picked out what he felt was the best looking keg in the house. I am excited to put it to use!
Carbonation volumes vary by temperature. Find a carbonation chart to get the idea. No need to prime, just insert the fermented uncarbonated beer into the keg, apply pressure, and wait.
You can carbonate in hours, too: At some cold temperature, set the pressure to 35 or 40, then rock or shake the keg. The CO2 will dissolve much faster. Do that for 5-10 minutes, then leave the pressure on overnight. Next day, reset pressure for volumes desired, wait a few hours, and done.
Without rocking the keg, itvtakes 2-3 days. At lower presdures (like 12 psi) it might take a week.
With a picnic tap, you must reduce keg pressure to pour, or you will get only foam. I usually just pull the pressure release until it almost stops hissing, then pour. Repressurize after.