Put down a dropcloth to protect your working space.
Scrub your bricks with soap and water using a nylon scrub brush. This gives you a clean and fresh surface to work with. Allow the brick to dry thoroughly after cleaning.
Prime the surface of the brick using spray primer. Choose a primer made to work specifically with masonry or an acrylic universal primer. Allow the primer to dry thoroughly. The instructions will tell you how long this should take.
Apply two coats of black paint to the primed brick using a paintbrush, allowing each coat to dry thoroughly.
Sand the paint down using 100-grit sandpaper. In some spots, keep the wear light; in others, sand until you can see the brick.
Wipe off all the dust using a clean cloth. At this point, you may leave the wall as is or go one step further and seal it using brick sealant.