Reputables Breeders and Disreputable Breeders In More Detail...
Requires you to meet the puppy in person.
Doesn't encourage you to meet the puppies.
Doesn't allow you to see where the puppies are raised.

Reputable breeders want you to meet and spend time with your potential puppy. This is great, as meeting your puppy will help ensure that he does not have any existing health or behavior problems and that he's being raised in a clean and appropriate environment. If the seller won't let you visit, it's likely they are hiding something. Don't fall for excuses like "We don't want diseases brought into our kennel." Walk away.
Insists on meeting you and your family in person and wants to know about you, a lot about you!
Doesn't ask many questions about you, your family, or your lifelong commitment to the pup.
Reputable breeders don't sell their puppies to strangers! They want to get to know you. They'll ask you about your family, if you rent or own your home, who will be caring for the pup, etc. etc.. Watch out for those who don't ask for much more than your credit card number.
Socializes the puppies to people, places, and things.
Doesn't socialize their pups to everyday people, places, and things.
Socialization is positive exposure to people, places, and things. It helps pups respond normally to everyday situations for the rest of their lives. It is absolutely critical that a puppy has been well-socialized. Make sure your future pup has been exposed to men, women, children, and household and real-world environments. If this isn't done, the dog is at risk for serious behavior problems.

For great info on how to tell if a pup is well-socialized, check out Ian Dunbar's video.

Don't just take our word on it, check out Dr. Nick Dodman's book, "Puppy's First Steps"
Has a veterinarian individually examine and vaccinate each puppy and has verifiable proof of this.
Provides no legitimate proof of vaccinations or examinations by a licensed veterinarian.
Proof of veterinary care is NOT a vaccination schedule with dates written on it by the seller. This is a common way sellers will deceive puppy buyers. True proof is paperwork from a licensed veterinarian. All puppies should have been vaccinated and examined by a licensed vet and you should be provided with paperwork that details the results of the exams.
Knows about the breed's predispositions to certain genetic problems and has had their dogs tested for them.
Doesn't screen for inherited disorders or has fraudulent documents.
All purebred dogs are at risk for genetic problems that are common in their breed. Reputable breeders are very aware of this and have the parents and/or puppies tested to ensure they are not creating dogs that will suffer. Verifiable proof of the results of these tests should be available. We encourage you to investigate the health issues in your breed. Visit the PupQuest Health Screening Info for more in-depth info.
Raises puppies in the home, not a kennel.
Raises puppies outside or in a kennel.
Your pup is going to live in a home, so he needs to be socialized to life in one from day one! That way, he can get familiarized with all he'll encounter in daily life: people, sights, smells, and sounds. Puppies who grow up separated from people - like in a garage, basement, or outdoor kennel, don't get the exposure they need to grow into friendly, outgoing companions.
Happily and proudly introduces you to the parents of the puppies.
Doesn't allow you to meet the parents, or at least the mother.
The parents are a sneak-peek of the dog your puppy will become. They should be healthy and friendly! If you're concerned about the health or behavior of the parents, don't buy a puppy from that seller-they're likely to have the same problems!
For easy info on what to look for, check out DogStarDaily's "How to Choose a Good Breeder".

If mom isn't on the premises, the seller may be buying the puppies from puppy farms and shipping them in.
Has healthy, long-lived adult dogs and contact info for previous buyers.
Has no clue where previous pups are living now.
The health and lifespan of a breeder's dogs are a sneak peek into the pups' futures. Find out as much as you can about them. Speak to people who own adult dogs bought from your breeder. Have there been any recurring medical problems like chronic ear infections? Do any of them have high-maintenance health issues like food allergies? Epilepsy? How long do the dogs generally live for?
Is able to knowledgeably answer all of your questions.
Seems more like a salesperson than a dog person.
Watch out for sellers who don't seem to know much about the breed or who give you that smooth-talkin' salesman vibe. Reputable breeders are dog-savvy and know their breed and their own dogs well. Ask the breeder questions about everything from the breed's characteristic traits to their own dogs' health and training.
Will take their pups back at any point in their lives.
Won't take a pup back after a certain length of time or at all.
Any reputable breeder will take a puppy back into their home at any point in her life if you can no longer keep her. A life-long commitment to each and every puppy produced is a sign of a reputable breeder.
Is involved with local and national breed clubs and abides by their Code of Ethics
Shows no interest in the breed other than selling them.
Reputable breeders are actively associated with national breed clubs. They participate in breed activities such as herding, agility, showing, etc. A lack of involvement is a red flag.
Follows the above PupQuest criteria
Wants to arrange to ship the puppy to you on a plane or to meet you in a parking lot or other public location to exchange money for the pup.
A seller asking you to make a business transaction in a public place is and always will be suspect. Reputable breeders want to check you out and protect their puppies, they would never ship one on a potentially traumatic flight to a stranger.
Raises only one or two breeds.
Is licensed by the USDA and/or has many breeds available.
A United States Department of Agriculture license is a red flag that a seller is a puppy farm. Reputable breeders are committed to only one or two breeds. If a seller is advertising multiple breeds, it is likely they are just following the trends to make money on the “breed du jour”. Keep your eyes peeled for their tricks: separate ads for different breeds from the same place can be deceiving.