Take a stance that is vertical jump width. The bar should be placed over the mid-foot, 2-3 inches away from shins. Take a grip just outside the legs so your arms clear your body. Use a double overhand grip if possible. The hands should grip the bar such that the bar is at the place where the fingers join the palm. Bend your knees so the shins touch the bar. Your scapula should be over the bar so that your shoulders are forward of the bar. Arch your lower back and lift the chest. The elbows should be completely straight.
Squeeze the chest and pull the bar up along the skin of the shins and thighs. Each rep should start from a dead stop. At the top of the pull, lift the chest and pull the shoulders back. At lockout, the hips and knees should be fully extended, shoulders back, and eyes looking straight forward. (But don't exaggerate the shoulder pull and back arching.) As you set the bar down, lift your chest and arch your back.
The going down phase should be faster than the going up phase. Deload on each rep.
As you go up, the knee angle changes first. The angle of the back with the floor doesn't change until the bar passes the knees.
The back angle depends on your personal body shape. Long torso, short legs give a more vertical back angle and vice versa.
You can also get this information in a 3" x 5" deadlift quick reference card.