Grip the bar just outside of shoulder width, such that the forearms are vertical. Place your thumbs around the bar with the weight as close to the heel of the hand as possible. Rotate the elbows forward so that they are in front of the bar and pull the shoulders forward so that the bar rests on the deltoid or chest. Your stance should be 10-12 inches between the heels.
Look straight ahead and at the wall. Lift the chest, take a deep breath, and hold it during the entire rep. Lean back slightly.
Drive the bar over your head. To lockout, straighten your elbows and shrug your shoulders up. As soon as the bar crosses the top of your forehead, move your torso forward under the bar and lockout. At lockout, the bar should be behind the neck.
Don't let the shoulders slide forward during the movement. Keep the shoulder blades retracted and tight. Keep the bar close to the shoulder at all times. Visualize pushing the bar by your face, scraping the nose. Keep your body in a tight, squeezed column. Squeeze the abs to maintain the tight column.
You can also get this information in a 3" x 5" press quick reference card.