Find the studs in the wall to which the desk will be installed using the stud finder. Mark their locations clearly on each side of the stud using the pencil. Measure the distance between the center of each stud to the next and write this distance down.
Arrange the heavy-duty brackets on the underside of the desk shelf board, the same distance apart from center to center as the wall studs were found to be. Mark the locations of the various bracket hole attachments using the pencil. Pre-drill these bracket holes in the shelf board using a drill bit which has a diameter that is an eighth of an inch smaller than the diameter of the wood screws. Attach the brackets to the shelf board using the 1-inch wood screws.
Position the assembled shelf desk against the wall and set the carpenter's level on the desk surface to find a straight position for the shelf. Establish a level desk surface and mark the heavy duty bracket holes in the wall using the pencil. Predrill these holes following the same procedure as before, but being sure to encounter the wooden studs with each screw. Attach the shelf to the wall using the 2-inch wood screws.