Mark the lumber for the frame of the floor. Place the two 2-by-6-by-96-inch boards on a worktable. Measure from one end and make marks at 1 1/2, 23 1/4, 24 3/4, 47 1/4, 48 3/4, 71 1/4, 72 3/4 and 94 1/2 inches. Place the framing square on the marks and draw lines across the two pieces of lumber.
To build the floor, secure the 2-by-6-by-70 1/2-inch lumber between the 96-inch pieces with 3-inch deck screws. Secure one on each end of the 96-inch piece and one between each of the line pairs drawn. Secure the plywood on the floor assembly with 1 1/2-inch deck screws. Place the floor in the desired location.
Build the back wall of the shed. Put the four pieces of 2-by-4-by-96 inch lumber on a worktable. Measure from one end and make marks at 1 1/2, 23 1/4, 24 3/4, 47 1/4, 48 3/4, 71 1/4, 72 3/4 and 94 1/2 inches. Place the framing square on the marks and draw lines as before. Secure five 2-by-4-by-82 1/2-inch boards between the 96-inch pieces as you did the 2-by-6s.
Construct the front wall. Set the 2-by-4-by-70 1/2-inch lumber between the remaining 96-inch pieces and secure them as the others.
Make the two side walls. Put the 2-by-4-by-65-inch lumber on the worktable. Measure from one end and make marks at 1 1/2, 27 1/2, 29, 51 1/2, 53 and 64 1/2 inches. Draw lines as before and secure the remaining eight pieces of 70 1/2-inch lumber between the 65-inch pieces as before.
Secure the four walls to the floor and each other. Stand the back wall of the shed on the floor and secure it in place with 3-inch deck screws. Stand the sidewalls in next and secure them in the same manner, followed by the front wall. Secure the sidewalls to the front and back walls in the corners with 3-inch deck screws.
Mark and install the first block on top of the back wall. Set a stepladder at one of the back corners. Make a mark on top of the back wall 1 1/2 inches from the end of the back wall. Lay a 2-by-4-by-22 1/2-inch block flat on top of the back wall and even with the mark. Secure it with 3-inch deck screws. Repeat this on the top of the front wall from the same side of the shed.
Secure the rafters to the blocks. The rafters are the 2-by-4-by-72-inch pieces of lumber. Stand the first rafter on top of the back and front walls so that one of its narrow sides is facing up. Hold it against the block and secure the rafter to the block with 3-inch deck screws. Secure the next rafter to the other end of the block. Secure the next 22 1/2-inch block on top of the walls and then the next rafter. Repeat this until all the rafters are installed.
Fasten the corrugated roofing to the rafters with the screws that have rubber grommets on them. Install the siding on the outside of the walls with the box nails. Cut the bottom of the door to fit in the opening on whichever end of the shed you choose. Next, measure from the top of the door to the top of the hinges, mark the stud in the door opening accordingly and install the door with the wood screws.