Storage sheds, garages and children's playhouses are usually afterthoughts after you build a house. When you build such a structure, you can turn it into a very classy complement to your home by using the same colour siding and the same kind of roof shingles. Installing these shingles is something you can easily do yourself with the proper tools, techniques and matching shingles. (You can get the shingle style number from the contractor who did your roof and then buy them from the shingle manufacturer or a hardware store.)
Unroll roofing felt on the roof's plywood top. Staple it down securely with staples around the edge and every foot or so in open space on the roofing felt. Cover the entire roof with roofing felt.
Nail the shingles flush with the base of the roof. Nail the shingles down one row at a time, using three to four nails per shingle. Hammer the nails into the top tar area of the shingle, with the three coloured tabs of the shingle on the bottom.
Start the next row of shingles and make sure you offset the seam on the shingle tabs. (As displayed in the diagram, each shingle's tab on the row above should be halfway offsetting with the seam of the shingle below it.) Cut off the part of the shingle that is hanging off the side of the roof.
Nail down ridge cap shingles on the peak of your roof (once you reach the peak of the roof on both sides with normal shingles).
Always be aware of your location on a roof to avoid falling off.