Remove all items on the bookcase, as well as the shelves, if possible. Move the bookcase to a well-ventilated work area such as a garage or outdoor deck or set the bookcase in the center of the room away from other surfaces you don’t want paint on. Make sure your work area is dry and free of dust. Use painter’s tape to secure a large drop cloth to the floor to protect it from spills.
Primer and paint do not adhere to dirt, so make sure you properly clean surfaces before you start. Use a mild solution of detergent and water, and scrub it thoroughly with a sponge or soft brush. Rinse with water to remove any soap residue and allow it to dry thoroughly.