Before deciding where to adopt a puppy, it's important to figure out what kind of puppy you're looking for.
One source for a purebred puppy or dog is through a reputable breeder. Most communities have a kennel club that maintains a breeder’s referral service for prospective adopters. These services often are found on the kennel club’s website or in the pet advertisements of a local paper. Select a breeder who has an established reputation, is knowledgeable about both the attributes and the faults of their breed and is genuinely concerned with the well–being and long–term care of his or her puppies. For some breeds, genetic testing is available to diagnose known problems. Many reputable breeders will utilize those tests when available.
For mixed-breed dogs and some purebreds, community animal shelters or breed rescue groups are a great source. Select a shelter or rescue organization that provides basic health care and temperament evaluations. These do not guarantee lifelong health but should give you a good idea about the general condition of your future family member.