Inspectapedia's "Installation Recommendations for Asphalt Shingle Roofs" can serve as a training manual for new hires. This one-stop reference site outlines best roofing practices, including installation temperature, shingle sealing methods, shingle course offsets, asphalt shingle nailing location and specifications, low slope and steep slope limits for asphalt shingles, and roof flashing at building eaves and around skylights.   Read more.