Lots and lots of research! What breed are you looking at?
I would join a local breed club and go to some local shows or field trials etc etc. See where those people get their dogs,if they are breeding.
Here are some basic things to look at
"-How knowledgeable is the breeder about this particular breed? Are they familiar with its historical origins? Can they educate you about the breed's disadvantages - especially genetic predisposition to health problems and characteristics like shedding, slobber, dominance, inter-dog aggression, etc. that may make owning the breed a challenge? Beware of anyone who sounds like a salesman and tells you that their breed has no disadvantages! Good breeders will play devil's advocate.
--Are the breeder's dogs screened for genetic health defects like hip dysplasia, eye disorders, hypothyroidism, Von Willebrand's disease, epilepsy, cardiac conditions, and anything else that is common in the breed? Can they provide you with proof, e.g., CERF and OFA certification and other relevant veterinary documentation? A good breeder will welcome your concern and be glad to offer the requested information - beware of anyone who is defensive! An excellent breeder will candidly discuss the health of their line of dogs, including the problems that have cropped up. Even good breeders can produce unhealthy dogs on occasion. The difference is that the good breeder is on a mission to find and remove those genetic influences from their breeding lines. The irresponsible breeder approaches health in a haphazard manner.
--Does the breeder have any old dogs on the premises? How long have their own dogs lived, and from what have they died? Beware of the person who sells off their adult dogs that are retired from showing and breeding. You want a breeder who loves the breed, not someone who loves to breed.
--How many breeds is this person breeding? Ideally, someone will have a special interest in only one breed (perhaps two). A Jack-of-all-Breeds truly is a master of none. How many litters does the breeder have in any given year? A good breeder may breed one or two litters, or may not breed at all for a year or more between litters. More is never better. Anyone who is producing a large number of dogs is probably doing it at the expense of quality.
--Are the breeder's dogs kennel dogs or house pets? While it is sanitary to keep large numbers of dogs outside in a kennel, you want a breeder who keeps their dogs in the house with the family. Breeders who keep their dogs in kennels may have temperament defects (like excessive dominance) of which they are not even aware. Puppies should be raised inside an active home to begin socializing them to a household environment.
--Will the breeder provide you with the names of their veterinarian and several past purchasers to serve as references? If given a choice, request pet references. Certainly a professional trainer will be able to handle a tough puppy, but what about a family with three kids and a cat? If the latter just loves the temperament of their dog, that speaks volumes. Ask the breeder about the homes that haven't worked out. There are bound to be some. Is the breeder honest that they made a poor placement, sympathetic to someone who underwent a life change that necessitated returning a dog, blunt that they produced a problem dog... or is the breeder bitter and accusatory about the person who bought the dog? Beware of the narrow-minded breeder who places blame on everyone but themselves.
--What kind of guarantees does the breeder offer? Most will offer a replacement puppy or refund of purchase price if your puppy manifests a serious genetic defect. Any responsible breeder will want to keep in touch with you and be informed if your dog develops health problems. The better ones may ask you to have your pet OFA and/or CERF screened when it is old enough (as your dog reflects on their breeding stock). Truly caring breeders will insist that you return your puppy to them if you are unable to keep it for any reason during its entire life.
--Does the breeder expect to sell you a puppy with strings attached? Concerned, responsible breeders will insist that you neuter your pet puppy as soon as it is old enough. They may have you sign a contract to this effect, or they may sell the puppy with limited registration (which means that if you do breed it, you cannot register the offspring). Remarkable breeders will pediatrically neuter puppies before sending them off to their new homes. This is a very good sign in a breeder, so much so that I would be suspicious of any breeder who does not insist on neutering.
--On the other hand, beware of any breeder who tries to sucker you into a breeding contract. They will treat you like you're stupid by flattering you and trying to con you into agreeing to keep your pet intact and breeding one or more litters, giving the breeder back one or more puppies from each litter. This is the biggest scam around. You get stuck with the expense and inconvenience (not to mention health risks) of keeping an intact animal and then providing the breeder with free puppies. If a breeder tries to talk you into this kind of pyramid scheme, find another breeder.
--At what age does the breeder send puppies to their new homes? Avoid any breeder who wants to send home a puppy younger than seven weeks. Many good breeders will release puppies at 8 weeks, but as long as the puppy is being actively socialized, it is arguably better to wait until 10 or 12 weeks.
--What does the breeder do to socialize their puppies? Ask them for specifics. Good breeders will have lots of toys and activities to which to expose their puppies. Mild stress is excellent for making puppies resilient later in life. A breeder who allows their puppies to experience different sounds, surfaces, etc. and meet different people is trying hard. A breeder who keeps their puppies in some sort of ultra-sanitary, almost sterile vacuum is doing the puppies a great disservice. Puppies raised in a kennel should be avoided.
--A good breeder will be very interested in who you are and somewhat choosy about whether you are able to provide an adequate home for one of their cherished pups. A breeder who wants to see your home, your kids, your spouse, your other pets, proof of your fencing, or talk to your veterinarian is simply trying to make sure that you will take good care of their pup. Do not resent this. Good breeders want to keep in touch with you after you've purchased a puppy and will be there for you with support and advice later on. Avoid breeders who take credit card orders over the internet and ship puppies to anyone who wants them. NO responsible breeder will sell a puppy to a pet store or other broker for resale.
--A good breeder will participate in breed rescue efforts for the breed they love. This is important. Anyone who scoffs at breed rescue or is not personally involved in it in any way is someone to be avoided. Often the best place to begin your search for a good breeder is to ask breed rescue volunteers for their recommendations.
--Good breeders think ahead and make reservations in advance for the puppies they will produce. You may have to wait for a puppy, but that's not a bad thing. Beware of someone who first creates puppies and then worries about how to disperse them.
--What does the breeder do for a living? Dog breeding should be an avocation. Avoid anyone who makes their living through breeding dogs! The corners they cut financially may be at your expense.
--Are the premises clean and orderly? Are the breeder’s dogs healthy in appearance? It can be a messy proposition to raise a litter of puppies, but puppies should not be wallowing in waste, covered with fleas, or otherwise appear neglected. Keep in mind that many longhaired bitches will shed their coats heavily during this time, so if the puppies’ mother appears a little ratty it is not necessarily inappropriate or unusual.
--Do you like the temperaments of the puppies' parents? Remember, temperament is genetic! Avoid puppies from bitches that demonstrate any aggression or shyness. Specifically inquire about possessiveness (food and object guarding), inter-dog aggression, defensiveness about being handled, etc. Accept no excuses for undesirable behavior. Don't be afraid to ask the breeder to demonstrate the *****'s good temperament to you.
--Has the breeder or will the breeder allow you to temperament test the litter? While puppy-testing is not especially predictive of adult temperament, it’s an attempt to gauge a puppy’s personality so that it can be best matched with a new owner. Ask the breeder's permission before doing anything to a puppy. No potential buyer has the right to do anything to a puppy which a breeder perceives as potentially harmful.
--Does your breeder respect veterinarians, trainers, groomers, breeders, and other peer professionals in the dog world? Beware of breeders who are paranoid or hostile towards other professionals. One cannot operate competently in a vacuum, and in general, good breeders are socially well-networked. They are liked, like others, and respect competent professionals in their field. A good breeder should make the effort the know other good breeders (especially of their own breed). It is important for a breeder to strive to improve their knowledge and understanding of their breed and submit to peer critique, even if it is not necessarily formalized (as in the show ring).
Yikes....can anyone be that perfect? I have 3 jobs and also have my dogs, I don't have time for breed rescues, or to go to breed club meetings.. In this economy I'm just trying to survive and provide my pups with the best food, bedding and vet care.Does this mean I'm a bad breeder? Heck no... to this date, none of my puppies have ever been in a shelter or rescue, my client know they can bring their dog to me and I will find a suitable home.. like the client who had terminal pancreatic cancer. I did manage to turn such tragedy into the best possible solution for all. This is 6 years of breeding, showing and loving my dogs. And I don't have more than 2 litters a year.... I don't have the time.... My best advice is use your common sense and don't be afraid to walk away from a breeder empty handed. A good breeder will not pressure you to take a puppy.