Measure the space where the bookshelf will go
Decide the bookshelf height, width, and depth
Choose the material, such as plywood, solid wood, or MDF
Gather tools, including saw, drill, screws, tape measure, level, sandpaper, and clamps
Cut the side panels, top, bottom, shelves, and back panel to size
Sand all cut edges and surfaces
Mark shelf positions on the side panels
Drill pilot holes for screws or shelf pins
Attach the top, bottom, and side panels together
Install the shelves at the marked positions
Attach the back panel
Fill screw holes if needed
Sand the assembled bookshelf again
Paint, stain, or seal the bookshelf
Let the finish dry completely
Place the bookshelf in position
Anchor the bookshelf to the wall if needed
Load books onto the shelves