A great place to start is with the
American Shetland Sheepdog Association, including their page on
finding a puppy.
You can
find ASSA member breeders. While ASSA membership is not a guarantee, it does indicate that the breeder is involved in the sport of dogs (not just breeding puppies to make more puppies), is part of a community of breeders, and has pledged to a code of ethics.
You can also find
local Sheltie clubs, which is also an excellent place to start. They will be able to connect you to breeders and guide you in choosing a reputable one.
I encourage you to consider widening your geographical search a bit. The best breeder for you may be a long drive (or even a plane ride) away.
