Watch this video from This Old House to learn how to repair shingle siding.
1 Make a story pole from a straight 1x3; mark locations of shingle courses on pole.
2 Use pitchfork to remove all damaged shingles from house.
3 Peel off any paper or housewrap; inspect the condition of sheathing.
4 Securely nail any loose sheathing to the wall studs with 3-inch galvanized nails.
5 Replace damaged shingles in original starter course with new shingles.
6 Staple rosin paper over sheathing.
7 Use the story pole to mark the location of the first shingle course.
8 Start nailing on shingles at the corner, leaving 1/8 inch space in between shingles.
9 Plane the corner shingle flush with house wall.
10 Install the opposite corner shingle and plane it flush with first corner shingle.
11 Using the story pole, mark the location of the second shingle course.
12 Snap a chalkline from story-pole mark to existing shingles of second course.
13 Install second-course shingles starting at the corner, overlap corner shingles to create a braided or woven corner.
14 Continue nailing shingles up the wall, using the story pole and chalk lines to align the new courses with the old ones.
15 To prevent corner shingles from curling, secure them with 2-inch stainless steel nails.