Measure the wall space and decide the bookcase dimensions
Check for outlets, vents, baseboards, and wall studs
Choose the bookcase style, depth, height, and shelf spacing
Gather materials, tools, and hardware
Remove any existing trim or obstacles where the bookcase will sit
Mark the layout on the wall and floor
Build the side panels, top, bottom, and shelves
Cut openings for outlets or vents if needed
Assemble the bookcase frame
Secure the frame to wall studs
Level and shim the unit as needed
Attach face frames, trim, or molding
Fill nail holes, seams, and gaps with wood filler or caulk
Sand all surfaces smooth
Prime and paint or stain the bookcase
Install adjustable shelves or fixed shelves
Reinstall baseboards or add built-in trim around the edges
Load the bookcase after the finish is fully dry