If you are using wood dowels to hold the mdf bookend sections securely together, drill holes for the dowels on the end of the side where it adjoins the back. Mark and drill holes for the dowels on the back to match. Drill holes in the base where it adjoins the sides and back and make corresponding holes for the dowels on the back and side. Fit the dowels and glue the back to the base, clamp in place and allow the glue to set. Line up the side and glue it to the base and side, clamping it securely in place. Allow the glue to dry.


