Quick answer:

It is wise to use your parking brake any time you park, but especially when you are parking on a hill. Before you turn off the car, it’s important to angle the wheels to prevent your car from rolling into traffic if your parking brake fails.

• When parking downhill, turn the steering wheel to the right (toward the curb).
• When parking uphill, turn the steering wheel to the left (toward the street).
• Important: if there is no curb when parking uphill, you should turn the wheel to the right, instead (read more below).