@Classic Brewing CoSome sound advice here from @ozdevil
Fill your keg with beer, connect gas bottle and set regulator to 30psi.
Fill the keg with gas until it's at pressure.
Release the pressure by pulling on the pressure release valve.
Repeat the fill and release process a couple of times to purge oxygen out of the headspace.
Finally - fill with gas until full at 30psi.
Disconnect the gas bottle and store your keg somewhere temperature stable.
When it comes time, don't forget to carbonate your beer before you connect to your tap to serve. Your beer must be cold. You can either do this quickly at high pressure by agitating the keg (the "rock and roll" method) or over the course of a week with the keg connected to gas at lower pressure whilst stored in the fridge.
If you have one of these gas connects on your bottle:
You have the advantage that it makes noise when the gas is flowing through it which assists you to know when your keg is up to pressure.
If you can get another gas bottle (yes I know more $$) then you can use one for serving that is permanently attached to your fridge and the other for purging and carbonating.