The following safety points cannot be overemphasized:
Always block the opposite wheel or wheels to keep the vehicle from rolling off the jack.
When raising the front of the vehicle, firmly apply the parking brake.
When the drive wheels are to remain on the ground, leave the vehicle in gear to help prevent it from rolling.
Always use jackstands to support the vehicle when you are working underneath. Place the stands beneath the vehicle's jacking brackets. Before climbing underneath, rock the vehicle a bit to make sure it is firmly supported.
Never use a jack at the lateral rod or the rear suspension assembly on a FWD vehicle.
In order to prevent scaring of the centermember on FWD vehicle, or crossmember on AWD vehicle, place a piece of cloth or rubber pad on the jack's contact surface. This will prevent the formation of corrosion caused by damage to the protective coating.
A floor jack must never be used on any part of the underbody.
Do not attempt to raise one entire side of the vehicle by placing the jack midway between he front and the rear wheels. This practice may result in permanent damage to the body.