A small garden shed is a good way to try your hand installing cedar shingles. You will use the same installation techniques, although on a smaller scale. Cedar shingles will last for decades before they need replacing.
Cover the roof with roofing felt. Use a hammer stapler to fasten it down, applying a staple every 12 to 14 inches.
Position the first shingle so its end overhangs the edge of the roof by 1 1/4 to 1 1/2 inches. Secure it to the roof by driving in two nails near the top edge of the shingle, about 1 inch below its top edge.
Put the next shingle about one-eighth to one-quarter of an inch away from the edge of the first shingle. This leaves room for the shingles to contract and expand. Ensure the second shingle overhangs the edge of the roof by the same amount as the first shingle. Attach the shingle to the roof with two nails driven in near its top edge.
Apply the remaining shingles in the first row using the same method.
Apply a second layer of shingles directly on top of the first row. This adds an extra-high layer for the edge of the roof, which will create more space between rain and snow runoff and the edge of the roof, where runoff can collect.
Split a shingle in half vertically for the first shingle in the third coarse of shingles. This will create the staggered pattern, similar to traditional bricks. Cut down the center of the back of the shingle and snap it in half with your hands. The singles are installed so they cover the spaces between the shingles in the row below. Position the shingles in the third row so the vertical center falls above the gap between two shingles in the first and second rows, which are installed one on top of the other.
Use a small piece of shingle as a template to position each shingle so it covers about half of the shingles below it in the previous row and leaves about half of these shingles exposed. This is called "the reveal" of the shingles, and it should be the same on every shingle, which is why it's beneficial to have a template with which to measure the reveal on each single.
Place special V-shaped cedar shingles on the ridgeline at the top of the roof. Install them after the other shingles are installed on the rest of the shed roof.