**N04 Assembly:** cut all boards to length, drill 3/32 in pilot holes, glue and screw shelves between the sides, clamp 30 min. **N08 Load testing:** load 25 lb per shelf for 24 h, mid-span deflection must stay under 1/8 in. **N10 Sanding and finish:** sand 120 then 220 grit, remove dust, apply 2 coats water-based polyurethane, 4 h drying between coats. **N11 Beginner mistakes:** always drill pilot holes to avoid splitting, never over-tighten screws, verify squareness before the glue sets. See also [[Bookshelf Materials]] [[Bookshelf Safety]] [[Bookshelf Tools]]