If you are on a flat floor, it's much better to leave the car in neutral and leave the handbrake off. Jack the car from a central point on either the front cross tube or the rear chassis crossmember, and let the car's wheels roll as the jack rises. If there's a risk of the car rolling off the jack, then the surface isn't level enough to be jacking on safely in the first place.
Once you have the car at the right height, put the axle stands in position and lower the car onto the stands immediately. Never leave the car supported on just the jack for a moment longer than necessary. Once it's safely on the axle stands, you can chock the wheels.
