Collect all your materials and cut your pine boards to size. You'll need two side pieces at 36 inches, three shelf pieces at 24 inches, and a back support at 24 inches. Use a saw and measuring tape to ensure accurate cuts.
Use sandpaper to smooth all cut edges and surfaces of your wood pieces. Start with medium-grit sandpaper and finish with fine-grit for a smooth feel. This prevents splinters and helps the finish look great.
Lay the two side pieces flat and mark where your shelves will go. Space them evenly - try 10 inches apart for standard books. Use a pencil and square to draw straight lines across both sides at the same heights.
At each shelf marking, drill two pilot holes through the side pieces. These prevent the wood from splitting when you add screws. Make the holes slightly smaller than your screws.
Position one shelf piece between the side boards at your marked lines. Use clamps to hold it steady, then drive wood screws through the pilot holes into the shelf ends. Repeat for all three shelves.
Attach the back support piece horizontally across the top rear of the bookshelf. This adds stability and prevents wobbling. Screw it into both side pieces from the back.
Apply your choice of wood stain or paint to protect the wood and match your décor. Use a brush or cloth to apply evenly, following the wood grain. Let it dry completely according to product instructions.
Allow your finish to cure for 24 hours in a well-ventilated area. Once completely dry, move your bookshelf to its final location and start arranging your books. Place heavier items on lower shelves for stability.