Lay an oak board flat. Drill a 1/2-inch deep, 1/4-inch-diameter hole that is 2 inches below the top edge, and 1/2 inch away from the left edge. Drill another hole that is 1 inch above the bottom edge, and 2 inches away from the left edge. Drill one more hole that is 1 1/2 inches above the bottom edge and 1 inch away from the right edge. All of these holes are 1/2-inch deep. Repeat this step on the other board.
Position the boards on the edge, 31 inches apart, with the holes facing each other and aligned. Place a dab of glue inside each hole, and insert the ends of the dowels inside each of the holes. Gently squeeze the boards together so the dowels are in as far as they can go. Wipe any excess glue off with your tack cloth and let them dry.
Sand the CD holder with your sand paper and wipe it clean with your tack cloth. Apply your wood stain and let it dry according to the instructions. Rest your CDs on the two bottom dowels that rest in the two holes that were drilled last on each board. They should rest perpendicularly on the edge of these dowels.