The following video shows a demonstration of bodyweight squats:
Your feet should be a little wider than shoulder width apart and pointed out slightly. Squat down while sticking your butt far back and keep a slight arch in your back. Continue down until the crease of you hip dips below the top of your knee, while keeping your knees out wider than your toes. Keep your hamstrings tight throughout the movement, and lift back up to the starting position.