If you have decided on a Puppy then there are some fundamental things you must do and some places you should never buy from, and rules that you must adhere to whatever the breeder or seller tells you.
Rule 1. Never ever buy a Puppy from anywhere or anyone without being able to see at least one or preferably both the parents. There are places called Puppy Farms that are absolutely deplorable.
Puppies from these farms normally have major health and behavioural problems throughout their lives. This is caused mainly through poor breeding, bad sanitation, cheap food, and bad handling.
They are generally taken from their mother and siblings far too early causing socialisation problems with people and other dogs.
Do not let the word Farm give you the wrong impression. It may not be a farm but kennels that are clean, airy, and bright. On the face of it look like a professional establishment. If you cannot meet at least one parent or their are lots of different breeds of pups around, then do not even consider buying a puppy, you will almost certainly live to regret that rash decision.
Quite often these people will buy the whole litter at say £45 per dog from puppy farms in Ireland or Wales, then sell then on to you at £450.00 complete with fancy bogus pedigree certification.
Rule 2. Never buy a puppy from a pet shop or any other similar outlet; other animals are OK but not Dogs. You could be supporting the horrific trade in puppy-farmed dogs. I have even seen pups being sold at car boot sales. Many of the dogs sold in Pet Shops are from puppy farmers.
Rule 3. Never buy on impulse or because you feel sorry for a frightened or timid puppy.
Rule 4. Never take the word of a breeder or any seller who says you cannot meet any of the parents, or they skirt your questions re the parents. The excuses commonly used are the mothers ill or not available or at friends or they are selling a pup for someone else. Another scam is to meet you somewhere away from the so called breeders home. Or they will bring the pup to you. You must see the house, the kennels, and where the puppies are being kept. It is better if they are reared indoors.
Rule 5. Do not automatically believe that your dog is a pedigree. Just because they have supplied a certificate, especially if parents cannot be seen, some of these certificates are not worth the cheap paper they are printed on. I have a puppy at my classes at the time of writing this, with a full pedigree certificate, sold as a Cocker Spaniel yet it is clearly and without any shadow of a doubt an English Springer Spaniel.
Rule 6. Unless you are an experienced handler/dog owner then do not pick the puppy that bounds up to you and pushes all the others out the way in it's haste to get at you. This is normally the most dominant of the litter. Do not also go to the other end of the scale and pick the runt or the frightened one, because you feel sorry for it, you are taking on a whole heap of problems if you do.
The majority of all dog attacks are based on fear not aggression. You are far better off picking a pup from the middle rankings. The breeder if worth their salt, should be able to advise you on this. Alternatively you can employ a behaviourist or specialist who can assess the pups using specialised puppy assessment tests.
Rule 7. If you looking for puppies do not automatically think that if you go through the Kennel Club route that those dogs and breeders have all been personally checked or vetted by that organisation. This is not the case though an excellent and well meaning establishment, they really do not have the facilities nor the ability or time to check the credentials or bona fide of all the breeders on their books.
You may be better to go to the breed clubs of the type of dog you are looking for, as they generally know each individual professional breeder, and respect each other ethics and work. Contact the secretaries and they should be able to point you in the direction of available quality pups.