The first two books are very scientific/technical, but definitely worth reading if you want a thorough understanding of scent theory and search dog capabilities. The second two books provide a good, yet brief overview of scent theory.
Conover, Michael R. 2007. Predator-Prey Dynamics: The Role of Olfaction. Boca Raton, FL: CRC Press.
Helton, William S. 2009. Canine Ergonomics: The Science of Working Dogs. Boca Raton, FL: CRC Press.
Syrotuck, William G. 2000. Scent and the Scenting Dog. Mechanicsburg, PA: Barkleigh Productions, Inc.
Wnuk, Lorrie. 2010. In Search of Scent: Basic K9 Scent Theory Training. CreateSpace Independent Publishing Platform.
Another book that may be of great interest to lost pet professionals that use search dogs is Prada, Paola, Allison Curran, and Kenneth Furton. 2014. Human Scent Evidence. CRC Press.
Search Dog Training
There are many books available on training scent-detection dogs. These are a few of my favorites.
Albrecht, Kat. 2007. Dog Detectives: How to Train Your Dog to Find Lost Pets (Dogwise Training Manual). Wenatchee, WA: Dogwise Publishing.
Rice, John and Suzanne Clothier. 1996. Following Ghosts: Developing the Tracking Relationship. St Johnsville, NY: Flying Dog Press.
Schettler, Jeff. 2011. K-9 Trailing: The Straightest Path. Alpine Publications.
Susan Bulanda also has a good series of books on scent dog training and SAR work. She integrates scent theory into the training books more than the instruction manuals listed above.
Bulanda, Susan. 2014. Ready! Training the Search and Rescue Dog. Lumina Media.
Bulanda, Susan. 2002. Scentwork for Hunting Dogs. Doral Publishing.
Bulanda, Susan. 1999. Ready to Serve, Ready to Save: Strategies of Real-Life Search and Rescue Missions. Doral Publishing.
The last book doesn’t have training instructions, but it provides a useful perspective on how search & rescue dogs are used in different types of searches for missing people.
Unfortunately, there are not any websites specific to training lost pet search dogs. Here are some related websites on training police dogs, search & rescue dogs, hunting dogs, and conservation detection dogs. For more information on assistance training search dogs, see Pet Detective Information.
e-Training for Dogs: includes courses on training dogs for search and rescue and tracking for hunting.
i2iK9 with Steve White: police dog training.
Working Dogs for Conservation: trains dogs in area detection of rare wildlife, scat, and invasive wildlife species.