This has many different answers depending on who you ask. I will answer this question based on my own thoughts and beliefs! This is subject to change as research evolves in regards to health testing/puppy raising/etc.
One thing I want to mention off the bat is that you're not rescuing your puppy if you are buying from a backyard breeder. As soon as you give that backyard breeder your money, they will see that they can get money (their ultimate goal) from doing nothing and continue with their antics. If you are on the other side and planning to/currently are breeding, even if it's only once, please choose to do it correctly for the sake of the puppies being produced, their families, and the future of the breed.
By purchasing from a responsible breeder instead, you are helping to preserve the breeds and supporting those individuals who truly care about producing HEALTHY, HAPPY puppies.
Your breeder should be breeding only AKC/UKC registered dogs (There are other reputable registries overseas). Meaning both the parents of the puppies are actually registered with AKC. Any other registry (CKC, APRI, etc.) is less reputable no matter how hard people try to convince you.
Do not fall for the scam "the grandparents are registered but we didn't register the parents so the puppies cannot be registered" or "The parents are AKC registered but we are not registering the litter, therefore we are not offering AKC registration on the puppies". In these scenarios, most of the time the "breeders" are breeding two dogs that they legally should not be breeding. Do not get caught up in that, they will likely get in trouble for it and you don't want to be a part of that. You should ALWAYS have the option to have your puppy registerable with AKC. Full or limited rights will vary on the breeder, many responsible breeders do not sell full rights outright, especially to new breeders. They will require you health test/title the dog prior to gaining full rights.
Most pet owners think that being AKC registered really only shows that their puppy is purebred. I am going to tell you that being AKC registered shows you so much more! Not only can you go back in the lineage to look at where your puppy came from but you can also look into the health, longevity, color, breeder, titles, etc. of the past dogs. I, as a breeder, am constantly scouring pedigrees trying to learn as much as possible about This may be very handy, especially for health because when you are looking for your best friend, you want them to have the best possible chance at a long health life! Along with that, registering your puppy with AKC can also prove your ownership if you ever need to.
At a minimum, a responsible breeder for the Golden Retriever Breed should be conducting OFA hip/Pennhip, OFA elbow, OFA cardiac, and OFA eye exams, as well as DNA genetic testing for MD, DM, GRPRA 1&2, GRPRA-prcd, NCL and ICH (view my page on GR Genetic diseases to learn more). These are the recommended health testing per the Golden Retriever breed via OFA and AKC.
By completing these health testing requirements your breeder can 100% avoid recessive genetic diseases and prevent issues such as Hip/Elbow Dysplasia, Genetic Cataracts/Genetic Heart Diseases. While there is no guarantee with Hip/elbow/eye/cardiac issues, by doing the testing, your breeder can be sure that the parents do not have any issues, therefor minimizing the potential for issues in the potential offspring.
Do not fall for the excuse, "We are only breeding for one litter", "We are only breeding for pets", etc. Even if you are only breeding pets or only plan to have one litter doesn't mean your puppies are exempt from receiving deadly/life altering genetic diseases, health testing is just as important!
Also don't fall for "We don't need to health test because my vet said my dog is healthy and we have never seen any issues". Recessive genetic diseases cannot always be seen in the parent dogs BUT they can be passed onto the puppies and cause life altering issues or even death at a young age... Recessive genetic diseases like MD, DM, ICH, NCL, PRA 1&2, PRA-prcd are 100% avoidable!
Along with this, any reputable breeder will have health testing open to the public. There should be no secret in the results.
While titling may not be something that a pet owner thinks is necessary, there is a lot of benefit to finding a breeder who spends the time, effort, and money on helping their dogs achieve titles of some sort. Be that working titles (hunting, sport, therapy, canine good citizen, trick dog, etc.) or show titles, they all demonstrate that the breeder is more involved in their program and their individual dog's success than just having them as yard ornaments or breeding stock. Titling is very expensive, we can spend upwards of $1500 just one weekend at one single event. I wouldn't spend that if I didn't love my dogs and want them to succeed and do what they also love doing, as well as work on improving my overall program. These titles also show the temperament and trainability of the individual dog. A dog with a questionable temperament likely could not be going into public settings, with other dogs/people, earning titles. Some of these titles also take quite a bit of training to obtain so the dog has to have a good work ethic and desire to train to even think about earning titles. Titles will also show the potential of the puppies if you are looking for something more specific in a dog; sport, show, working, therapy, or service prospect.
Raising the puppies till 8 weeks minimum
Your puppy should be staying with his mom/siblings for at least 8 weeks. While your puppy will likely be weaned from its mom around 5-6 weeks, your puppy still has a lot of behavioral aspects they need to learn and develop with its siblings. It is important that they stay with their mom/siblings for the extra 2-3 weeks to learn behavioral manners and develop mentally a little more to begin learning as soon as they get into their new home.
Your puppy should come to you with age appropriate vaccinations, deworming, vet check, and microchip.
There really is no excuse for your puppy not having vaccination, deworming, vet check, and microchip. This is to ensure the puppy's health before coming into your own home. While the first vaccinations will not fully cover the puppy, it will help them get started on building a strong immune system. As for deworming, puppies are way too susceptible to parasites and parasites are everywhere (no, you are not exempt just because you don't live on a farm). Parasites are distributed most commonly by water and birds and I don't think anywhere can say they have no water and no birds, it is important to prevent them from the beginning rather than treat them in the future.
Anyone who raises puppies should be doing much more than simply giving the puppies a place to be raised and handing them off to their future parents. The breeder should be implementing Early Neurologic Stimulation right from the beginning. This includes handling them right from the beginning and introducing them to new things, sounds, smells, environments, etc. while they are growing up. By doing this, the puppy is better prepared for its brand new environment and adapts much easier. They are being taught to have to adapt in a positive manner from the get go! This also gets them learning much earlier so they can move right into their new home and start learning right away with their new family.
Any reputable breeder is willing to offer a health guarantee of some sort. The health guarantee doesn't say that issues won't happen, because a lot things are completely out of our control, but it states that IF something does happen, that breeder is willing to help support you in any way they can. This can be anything from offering a replacement to simply offering suggestions/help if something arises.
First Right of Recovery in Contract
Any responsible breeder should REQUIRE that if for any reason you cannot keep your puppy, the breeder gets it back. This ensures that the breeder is keeping track of the puppies they produced and they can make sure they are in good, quality homes. This also helps them make sure that none of their puppies end up in a shelter, rescue, or negative situation.
Puppies are raised in a CLEAN setting
It is no secret that puppies are messy and things can get messy real fast. Imagine one puppy pooping and peeing 2-4 times a day. Now multiply that by a litter of 6-12. A responsible breeder will be cleaning their potty area/bedding multiple times a day if necessary. When getting into the responsibility of raising a litter of puppies, you also take on the full time role of "pooper scooper"!