As a person that just brought a pup home in December, I'll put my 2¢ and anyone can take it or leave.
I started my search well before I lost my girl. Not trying to replace her, I just know we are a 2 dobe family.
I can't even begin to tell you how many breeders I investigated....hundreds!
I started with a list of what I wanted in a dog, health and temperament being at the top of the list. I also had a list of what is important in a breeder. That list included things like do they show/train their dogs? The contract they offered, yes a biggie for me because it includes things like when you have to alter the pup.
Websites, to me are a start but breeders are infamous for not keeping them them updated. That said, some things I saw on websites were definitely a deal breaker. For example the link posted above
Our Puppies was an instant NO WAY! the minute I saw the pups were $700. I would wonder about the care of the dogs if you sell pups for that price. If you are giving the right care, there is no way to keep the doors open.
I understand I have a long list of demands (I only touched on it....it goes on and on) but it was important for me to get the right pup and the right breeder. IMHO, it is important for a puppy buyer to know what is important, what flags to look for and to be patient and wait for the right choice, it pays off in the end.