Just to add to what Val has said...
Sadly, KC registration is NOT some sort of mark of quality in any way, neither is a breeder being KC Accredited. Those are part of the absolute, bare minimum standards to look for in a breeder, amongst other things. Puppy farmers are responsible for around 90% of KC registrations, which when you also consider Back Yard breeders (those with little knowledge breeding from pet dogs) and the fact that responsible breeder will only breed once every several years unless there are exceptional circumstances, once per year at absolute most (although that is too often IMO) doesn't leave that many KC registrations from responsible breeders. 
There are tens of thousands of dogs being put to sleep every single day, so anyone breeding should have an extremely good reason for doing so and also be prepapred to be responsible for the puppies they breed for their entire lives so as to try not to add to the rescue situation.
If you want a family dog, then the dog should be reared within a home or have daily access to a home and a lot of human company. A lot os very important socialisation happens within a litter and as someone very experienced who took on a rescue pup that hadn't had that, the difference in general socialisation and ease of toilet training is astounding!
Anyone looking for a puppy should go via the breed club. They will know which breeders are reputable and which aren't and if they aren't, they won't have anything to do with them. Be prepared to ask lots of questions and be asked even more, even personal questions about your home situation (whether you own or rent, married, how long you've been in a relationship, planned children etc) and financial situation. Ask how many litters the person breeds, which stud dogs they use and why (own the stud dog or nearby are dreadful answers!) whether they are keeping a pup themselves (they should be), how pups will be socialised, (will they have left the premises or been in a car before you get them) wormed, if they'll be vaccinated etc. What age they'll leave the breeder and why, whether Mum is allowed unlimited access to her pups etc. What health tests are done and what the results are and ask to see proof. What diet the litter will be reared on and why. Is it good quality? Will the pup be toulet traine dor partially toilet trained when you get it, will it have had any other training? Will the breeder be on hand 24/7 after you've taken the pup home for advice? Will the pups have been vet checked before you get them, do they suggest you take the pup to your own vet soon after you take it home for a check up and if something is wrong what will they do?
There are 1001 things to know to make sure you get a pup from a decent breeder. If you do not then you risk the pup being or becoming ill, having hereditary or congenital problems, having temprement problems or behaviour problems. If you don't buy from a decent breeder then you are encouraging the breeding of all those dogs that end up in rescue and put to sleep, because the vast majority of them are from irresponsible breeders and puppy farmers.
Of course, there are also puppies in rescue centres often, so a breeder isn't the only option, even for purebreeds.