My goal was to use up some scrap chip board shelving. It is nominally 12 inches wide and I have 5 feet 4 inches of it. I also used four door hinges I found at our local Restore, an outlet for donated building supplies, the proceeds of which fund homes built by Habitat for Humanity. Naturally, I used some 3/4 x #10 bevel head metal screws to fasten the hinges to the chip board pieces.
For tools I used sawhorses, a 7 1/4 inch circular saw, a measure, a square, a straight edge, "C" clamps, a drill, a screwdriver, and a pencil. I also made use of something I built
in another Instructable to assist in cutting stock with a circular saw. (I did modify it and will mention the additions to it when that part of this Instructable comes.)
Pictured is the shelving on my sawhorses. Note the text boxes for layout instructions. Make a pencil line. This line provides a gentle slope to the top of the desk that makes reading and writing on the desk more natural. By making this angle cut about a dozen inches inward from the end of the shelf, I can cut once and the same angle will be on both upright pieces.