Prepare the wood to be painted. If you have an unfinished crib that has never been painted, sand the wood, clean it with a cloth and apply a primer to seal the wood. For cribs that have been painted, you need to strip the paint, sand the wood, clean with a cloth and apply a primer. Wood finish can stain through paint, so you may need to use a primer designed to block bleeding.
Decide what color you want to paint the crib. You can use classic colors like blue for a boy or pink for a girl. Neutral colors are white, yellow and green. Most baby colors are pastel. If you want to use a pattern or stencil, pick colors that complement each other.
Buy your supplies. Antique cribs may have paint containing lead, so you need to make sure you clean the wood well. You want to use a paint that won't chip or flake and that can safely by ingested by a baby. Read the manufacturer's warnings to ensure that the paint is safe to use on a crib.
Paint the crib. A roll brush works better than a paint brush to get a smooth look. Spray paints can easily reach areas like the inside of slats, but may run. Allow the paint to dry before applying a second color of paint. You can use masking tape to block off areas that are different colors from the paint you are using.