This excerpt from the EZwoodshop.com "How to Build Anything" series includes an easy-to-print pilot hole guide template for keeping pilot holes perfectly aligned along the edge of a board.
Most of us know that drilling a pilot hole first is the best way to make sure fasteners go where we want them to go. But the location of that hole can be just as important as the hole itself. If it's not in the right place, you can easily ruin a project by splitting the fragile edges of the boards you're trying to join.
I like to use 1x6 and 1x12 boards to build small wood projects. The tricky part about joining pieces like this is making sure my pilot hole hits dead center on the 3/4" thickness of the board I'm driving into. If the hole ends up too far off center, I'm almost certain to split some wood somewhere on the project when I drive the screws.