Being a vinyl-siding contractor as well as a deck builder, I'm interested in low-maintenance alternatives, so now I use storm doors made of aluminum instead of wood for the panels.
Upper and lower tracks, F-channels for the sides, and H-channels used to join storm-door panels together and to the framing are supplied long. We cut them to length using a chop saw; a standard trim blade works well.
After bedding the base track in caulk, we screw it to the decking, then drill weep holes 3 inches from the ends and 16 inches on-center.
Next I install F-channels along the posts, again checking to make sure that the top and base tracks are perfectly aligned.
With the glass or screens removed to lighten the load and reduce the risk of damage, we join each pair of panels with an H-channel that's cut to fit between the top and bottom tracks.
We slide the joined pair of panels up into the deeper top track until they clear the bottom of the opening, then drop the panels into the base track.