The first thing to say about sheet mulching is that it saves a great deal of labour, and a great deal of water, while dispensing with the material that normally goes into a landfill. Thus mulching also saves money for public authorities, and produces an excellent soil. Before starting, plant any large trees or shrubs from the nursery as usual. Gently firm around the base of the tree.
Nitrogen starts off the process of reducing the carbon in the following layers.
Don't bother to dig, level, or weed the area. Your first attempt should be very close to the house, preferably starting from a foundation or path which is itself weed free. Thus you are protected from invasion of weeds from the rear, so to speak. Now, proceed to tile and overlap the area with sheet mulch material. This can be cardboard, hardboard, newspapers, old carpet, under felt, old mattresses or clothing, rotted palings or thin wood.