We don't usually breed our bitches until they are 2 years old or older, after they've had time to mature and finish their championships (except in special circumstances).  Puppies are whelped in the house and raised in the kitchen in a 4' wide kid's wading pool, with an 30" excersize pen enclosing it. This enclosure is a big part of the puppies' socialization process. The pen is short enough to reach in and pick the puppies up easily and being in our most used room in the house, they get used to commotion and loud noises.