There are several versions that are commercially available, but it takes very little time and material to make a very accurate shelf pin jig. I made this one in less than an hour from a single piece of 1 x 6 pine.
My preference is for a jig that uses a router to “drill” the holes, since it does such a clean cut and the depth of the holes is very controllable and consistent.
Another design point was to make it so that the router would not have to be lifted and lowered off the jig for each hole, but would sit on the jig and slip into notches for each cut. This really makes a big difference when you have a lot of holes to make, reducing arm fatigue greatly.

I started with a piece of pine that is 36″ long and 4-1/2″ wide. The first thing I did was to use the table saw to score a shallow cut 2″ from the edge. This is a convenient and accurate layout line for the pin holes that need to be drilled in the jig. I then used a 5/8″ forstner bit in my drill press to bore the holes. The 5/8″ size hole matches the 5/8″ outside diameter collar for my router base.
The first hole on each end of the jig is an index pin hole, and it was drilled 1/4″ diameter. These indexes allow the jig to be used for longer panels by slipping a 1/4″ dowel in the last hole cut and aligning the jig up for the next series of pins.

The jig is made up of four parts, cut from the 1 x 6 pine then glued back together to form the slot that allows the collar of the router to slip through. This is almost always my preferred way of construction for this type of thing, rather than cutting the slot out from the whole piece. It can be done either way, the main thing is that the notches are accurately laid out and machined.

The jig is very easy to use: just line it up with the end and edge of the panel you want the pin holes in, clamp it down and route the holes. The jig is exactly symmetrical, so it can be positioned any way with the same result.
Here are the dimensions for the jig:

Here’s a short video going through the building of it and a quick demonstration of the jig in action:

Here’s a more recent video using the jig for my kitchen cabinets:

I know I’ll get lots of use out of this jig, from storage cabinets for the shop to kitchen cabinets for my new house.