Most breeders will not let you take a pup to a strange area. If your in a club situation, the breeder can bring the pups to the training field. Is that big round stomach because it just finished eating and drinking or is it wormy. Talk to the breeder, find out what they are breeding for. Pick their minds.
Good breeders guarantee their pups.
I have seen two and three page agreements on puppy purchasing. If the pup has a genetic flaw that appears during the first year, the breeder should replace the pup with one from their next litter. Remember a guarantee is only as good as the person giving it. There is a lot more involved with puppy selection. This is just enough for a good conversation to start on this list.