[Slipknot]

I want to begin to finish off a room in the basement but would like to paint the concrete first to try to keep some humidity out as best as possible. The basement is dry, no serious leaks, no sump pump, never had water except those crazy rains/flood 2 years ago where the water table rose so high it came thru the cracks in the floor.
Now is the time to paint the walls before I cover them up and was wondering what product to use.
any opinions?
thanks