I have had a number of email questions about the best way to break in 8-ball. I don't know a specific, all inclusive answer, but there are a couple of fundamentals that you can "play" with.
First, remember that maximum cue ball energy is achieved with a "full in the face" hit on the nose of the rack. Place the cue ball anywhere on the head string. Using a center ball hit (or 1/4 tip above center), simply "throw" the stick at the nose, full in the face, with force. The cue should stay in the middle of the table after the break. Some players prefer top english to drive the cue through the rack, but this can leave you against the foot rail without a second shot.
Below is the "second ball hit." Place the cue ball on the head string about 3 or 4 inches from the side rail. Use inside spin and target the second ball, barely clearing the nose ball. This shot needs a lot of practice, but will spread the balls nicely, and you might make the 8-ball in the side on the break. Scratching in the corner is probable if the hit is too thin, or with no inside spin.
Billiard World Home Page