Ingredients

•  5 Gallons Apple Cider (Cub Foods Brand, Indian Summer - cheap stuff)
       •  make sure it doesn't have any potassium sorbate
•  2 lbs Light or Dark Brown Sugar
•  2 cans of Apple Juice Concentrate (to keg)
•  Dry Ale Yeast (I've used US-05, S04, Nottingham - it doesn't really matter)

Mix & Ferment
•  Sanitize fermenter of your choice
•  Add Brown Sugar to the fermenter
•  Pour Apple Cider over the sugar which will mix it up and aerate
•  Add Yeast
•  Ferment until done (usually goes to 1.000 or a little higher)
•  Sanitize secondary fermenter
•  Add 2.5 tsp of Potassium Sorbate to prevent further yeast growth
•  Rack cider on top of Potassium Sorbate and any other flavorings you wish to add (fruit, spices, etc.)
•  Let it sit for a week or two

Kegging
•  Sanitize a keg
•  If you got frozen concentrate, heat that in a pot on the stove until it's slightly warm and pour it in the bottom of the keg
         •  If you got non-frozen concentrate, just pour it into the keg
•  Rack the cider on top of the concentrate
•  Hit the keg with 30psi to seal the lid and vent headspace

I've had this cider on tap as short as 4 weeks, but I usually wait about 6. That's from start to finish, not aging in the keg. You can play around with different concentrates to get the level of sweetness that you want. Be careful with this stuff around guests, especially if they've already been drinking. It typically weighs in at around 7.5% ABV, so it can sneak up on them pretty quickly.