About.com and DoItYourself.com both offer step-by-step instructions on how to install roof shingles. About Home, which is part of About.com, provides a video tutorial along with a transcript of the steps. Do It Yourself gives information about choosing the right shingles and how to replace shingles that are damaged.
The first step in laying shingles, after laying down the tar paper, is to put down the starter shingles. Lay these shingles around the edge of the roof. Lay additional shingles over the starter shingles, working from the bottom of the roof to the top. Then, move to the next row of shingles and repeat the process. The best way to attach shingles to the roof is to use a roofing coiler and air compressor, rather than a hammer and nails.