The steps to building your own shed are laying the foundation, building the floor, adding the walls, framing the roof and detailing the door. Many of these tasks are composed of further steps. You finish the project by capping off the shed with finishing material such as shingles.
You create the shed foundation by laying either concrete blocks or treated-lumber skids, while for sloped sites you can use concrete blocks laid on compacted crushed limestone. Lay out and stake the four shed corners and dig the appropriate-size depressions, and afterwards put crushed rock into each depression. If you use concrete blocks, glue them together with construction adhesive.
Build the outside of the floor with pressure-treated 2x6 sill lumber, and use 16d galvanized nails for the floor joists. Place 3/4-inch tongue-and-groove plywood floor wood on the floor.
For the walls, place studs on 16-inch centers and cut the appropriate wall lengths. Be sure to leave a marking for the door location. T-111 vertical plywood siding is one option for the shed siding, and you can use 2x4 stock and 1/2-inch plywood for the window headers.
Create the starter roof frame on the ground, and then later install it onto the top of the shed. Finish by placing shingles and other finishing touches on the shed.