Make a two-shelf bookcase headboard fit for a queen -- queen size mattress that is. Instead of just taking existing bookcases and repurposing them, make your own custom shelves. This way you can stain or repaint the wood to your liking, instead of having a unit made of imitation wood. You then will have a bookcase headboard made of sturdy, genuine wood for a fraction of the price you would pay for a similar model at a furniture store.
Use a circular saw to cut the wood yourself according to the listed specifications or have the wood cut at your lumber store. Sand and stain the wood, or sand, prime and paint each piece of wood. Allow each piece to dry completely.
Turn the 54-by-12-by-1-inch pieces over so the fronts are facing you. These will be the side panels. Measure from the bottom up and take a pencil to mark lines on the left and right of each panel at 24 inches, 36 inches and 48 inches. The 24-inch line marks will be your placement reference for the front panel, and the 36 and 48-inch lines will be used as drill hole reference marks for the cleats that will hold the bookshelves.
Drill two pilot holes at the 36- and 48-inch mark lines on each side panel. Place the 1-by-1-inch wood pieces for the cleats on the bottom sides of the side panels, so that the top edge of each cleat aligns with the 36- and 48-inch mark lines. This will give you 12 inches of clearance on each shelf for placing books.
Use your drill and woodscrews -- working from the front side and drilling through to the bottom side -- to countersink the screws 2 inches from the right and left side edges of the panels to attach the cleats to the panels.
Stand the side panels on their sides. Use a stack of books to brace them. Place the 54-by-62-by-1/2-inch piece of plywood on top of the side panels. This will be the back panel. Adjust the placement of the panels so the plywood fits and the unit is aligned. Staple the plywood back to the side panels, every 6 inches.
Stand the unit upright. Use woodscrews to attach the 62-by-12-by-1/2-inch piece of wood to the top of the side panels. Staple the 24-by-62-by-1/2-inch piece of plywood to the sides of the side panels. This will be the front panel. Place the bookcase headboard into its final location. Insert the 50-by-12-by-2-inch wood pieces for the shelves.
Apply putty for painted surfaces or wood filler for stained surfaced to cover countersink holes. Allow it to dry. Paint or stain to complete your bookcase headboard project.
The front panel will give you pillow support. Consider using beadboard for the back and front panels to give the headboard a decorative country or craftsman-style look.