Measure the space where the media shelves will be installed. For purposes of this article, the space is 18 inches wide by 6 feet tall.
Measure the largest item that will be stored on the shelves -- height and depth. Some cases for special edition DVDs or VHS tapes are larger than average. Generally, a CD is 5 5/8 by 4 7/8 inches, a DVD is 5 3/8 by 7 1/2 inches and a VHS is 5 1/2 by 9 inches.
Lay the two 6 foot long boards next to each other on a flat surface with the 8-inch side down. On each board, measure 1 1/2 inches in from both sides. Using a long straight edge such as a yardstick, draw two parallel lines along the length of the board.
Measure and mark 2-inch increments along the parallel lines. Draw a line connecting the marks across both boards so the lines are perfectly matched.
Wrap a piece of tape one quarter inch from the tip of the quarter-inch drill bit. Center and drill a quarter-inch-deep hole where each of the vertical and horizontal lines intersect.
Turn the 6 foot boards so they face each other, with the holes on the inside. Place two 16 1/2-inch boards between the long boards, one at the top, butting against the inner edges and even with the ends, and one at the bottom.
Predrill through the sides of the long boards and into the ends of the short boards. Screw together with wood screws to make an open box.
Run a bead of wood glue on the 1-inch sides of the box. Place the hardboard over the box. Align the top, bottom and sides, then tap 1 inch brads through the hardboard and into the edges of the wood.
Stand the shelf unit up and place it in its permanent position. Place an L-bracket on the top of the shelf, pushing it against the wall. Predrill 1-inch-deep screw holes into the shelf. Screw the bracket to the shelf. Then drive a screw through the bracket and into the wall.
Insert shelf pins into the holes, spacing the shelves according to the height of your media collection, at 6-, 8- or 10-inch intervals. Place the shelves on the pins.