Most manufacturers include a template to simplify this part of the job. The template adheres to the door and shows where to drill the holes (Image 1). The placement of the template is important -- be aware of the location of the entrance door's handle and be certain that the storm-door handle won't interfere with it.
With the template in place, mark the holes for the hardware. Set the holes using a center punch. Using a 5/16" bit, drill the prepunched holes (Image 2). Follow it with a 7/8" spade bit to drill a hole for the deadbolt assembly (Image 3). Connect the interior and exterior latch through the door with the screws provided.
Line up the striker-plate to make sure it's even with the latch (Image 4); mark the striker-plate and screw it into place. Test the door and make sure it fastens properly.