I would get Real Flight G2 sim with the add on that has the Raptor 30. I'm a self taught heli pilot, but I was VERY proficient at flying airplanes before. The Raptor on Real Flight is very simmilar to real life, but the sim will let it slide back and forth ALOT more than it ever could in real life.

How much open space does your warehouse have? While you learn, it should be 50 FT on either side, MINIMUM. Plus, you need to have excellent ventilation because helicopters smoke alot more than any airplane. I can fog up my front yard with my chopper in about 5 minutes if there isnt any wind. The slick conrete floor in the warehouse will help you with learning to fly it. The concrete will let it slide alot, almost as much as real flight, so you can get better with holding it in one place without actually lifting it off the ground.

The best way to learn is to get an instructor. It's very hard to learn by yourself without any previous flying experience.