Have the lumber company cut all the boards to specification or do it yourself with a circular saw. Smooth all sides and edges of the boards with medium-grain sandpaper. Finish with a smooth, fine-grain sanding. Wipe away all of the dust and grit with the tack cloth.
Stain all sides and edges of the wood with a light coating of stain. Use disposable foam paintbrushes for this job. Give the wood at least two coats, drying thoroughly between coats. Give the wooden pieces two coats of acrylic finish. Dry thoroughly between coats.
Lay the two side boards that will form the right-hand leg and shelf support apparatus onto the work table. These boards measure ½-inch-by-29-inch-by-30-inches. Measure and mark halfway down the outsides of each board, ¼ inch in from each side, as well as in the center. Drill a pilot hole in each mark. Drop in a bit of wood glue to ensure a better bond. Use wood screws to attach the 12-inch-wide center shelf by screwing from the outside of the boards into the sides of the shelf.
Mark the bottom outside of the boards ¼ inch in and at the middle before drilling pilot holes for the bottom shelf. Drop in the glue and screw the bottom shelf in place.
On the 1-inch-by-30-inch-by-36-inch oak desk top, mark along both short side edges ¼ inch from the edge and every five inches across from front to back edge. Drill pilot holes into these marked spots and drop in glue. Attach the side-shelf portion on the right side by drilling from the top down into the right leg portion of the shelf assembly. It is not necessary to drill through into the left-hand portion of this shelf attachment because it is only 12 inches wide. Attach the left side by drilling down from the desk top into the left-side edge of the desk to form the left side of the desk.