STEP 1: Paint your brackets (if you wish)
before getting started. Then screw them into the bottom of the top rung of the ladder.
STEP 2: Place your shelf where you want to hang it, making sure it is level and drill pilot holes into the door or wall you are wishing to hang it on. Then screw through the brackets and into the pilot holes securing it in place.
STEP 3: Take a step back and make sure that the shelf is centered and level.