Instructions
Using a squat rack (if possible), position the bar so that it is inline with your upper chest. Take an even grip, duck under the bar and then place the bar on your upper back. Squeeze your shoulder blades together, and bring your feet together. Now stand up and away from the rack. Place your feet approximately shoulder width apart and your feet out at a slight angle. Keeping your head in a neutral position, squat down by bending at the knees and bringing your hips back and down. Descend until your thighs are just past parallel to the floor. Let the bar come to a complete stop and pause for two seconds. Ascend by extending knees and hips until your legs are straight.
Tips
If you have trouble with your knees caving in, focus on pushing your knees out hard as you descend and ascend.