Line up the pieces of wood as they will look in the final assembly. Clearly mark each piece of wood to indicate the top, the bottom, the front and the back. This will prevent confusion when you're fitting the pieces together.
Attach the dovetail bit to the router. Attach a template guide to the base of the router, surrounding the dovetail bit (Image 1).
Use the router to cut inside the crevices of the dovetail jig (Image 2). Make sure the template guide makes contact with the templates on the jig.
Repeat steps 2 through 4 for the second piece of wood, feeding it into the dovetail jigwith its bottom side facing up.
Apply a small amount of wood glue inside the joints, and join the two pieces of wood. If the dovetail cuts do not permit a perfect fit, use a small chisel or sandpaper to remove debris or wood from the crevices.