I built a book case and instead of using the tracks I usually use I decided on 1/4" shelf pins. The problem was drilling the holes square and level. I ended up making a jig from 1/4" pegboard, squared up so it was even with the holes in both dimensions. It worked great. Just drill through the holes you want with a brad point bit. As long as the bottom and back of your jig registers on the same edge, the holes will be perfect.