When I kegged my first brew I put mine co2 at 14...after two days I jacked it up to 20 for 24 hours...after that I dropped it back down to 8 for another 5 days ...it turned out glorious...just my two cents...good luck
I do the set and forget method. It takes about 1-2 weeks. After a week it's mostly carb'd, but after two its good to go.
30psi @ 66F if carbing at room temp.
12psi @ 38F if carbing in a fridge.
Under the section "Carbonation" it explains how to force carbonate a keg in a manner that will fully carbonate a soda keg in about 15 minutes. I've used this method exclusively and have had great results.
NOTE: The link will download a pdf file you can save on your computer to use as reference. It has a very useful chart for determining pressure required based on temperature and volumes of co2 desired.
I put the keg in the fridge for 12 hours to get it to temp. Then I apply 30psi for 36 hours, then back it down to serving pressure, 12 psi for 24 hours then take a pull on the tap handle and enjoy!