Susan G. Purdy, Pie in the Sky: Successful Baking at High Altitudes; 100 Cakes, Pies, Cookies, Breads, and Pastries Home-Tested for Baking at Sea Level, 3000, 5000, 70000, and 10000 feet (and Anywhere in Between) (New York: William Morrow, 2005).
If you bake, and you live above 3000 feet, then this book is for you. It’s an excellent resource for concrete, trustworthy advice about high-altitude baking. I love that every recipe has been tested. Calgary is at about 3500 feet, so the changes I need to make are minor, but it’s nice to have some solid information to turn to. This is an excellent resource!