If you have any experience with baby-proofing your home, it's not a far reach to puppy-proof it. If there are rooms where you absolutely DO NOT want your dog to enter, gates are the answer. They're available in every height and width; can be free standing, pressure mounted or wall mounted; and made of wood, metal or plastic. They range from inexpensive to high-end designer types. Once upon a time, when I was a kid, my father used two shutters placed about an inch off the floor. They swung back and forth like saloon doors and hooked in the middle to keep them closed. Actually, it wasn't a half bad idea. Just think how creative you could be with a little help from a home improvement center.
But as a dog trainer and dog lover, I must tell you that puppy-proofing starts with training. A dog, like any member of a household; and I throw that in for those of you who feel guilty restricting your dog's activities; must follow rules and adhere to boundaries from the beginning. If your dog is allowed to jump on the furniture, scratch the doors, run in and out of the house tracking dirt everywhere, that is what he will continue to do. Why? Because he can and you are the enabler. Instead, by investing time in good old-fashioned training, you'll keep your home décor investments solid.
Get your dog used to the fact that you will clean his paws when he comes in the house. I really like the new Dremel devices that file your dog's nails. It helps to keep the wood floors from being scratched, the carpeting from pulling and the couch from ripping.
If a puppy is destructive when you leave him alone, then confine him until you return. Do I think it's cruel to confine a dog? I will say that I do not condone kenneling all day - I think that is cruel. But using short periods of confinement while you teach your dog to have freedom without destructive behavior, is acceptable. Think about the alternative. You come home to find your house in shambles and then punish the dog or worse; send him to a shelter.
In addition to the perils of puppyhood, the major causes of destructive behavior in dogs are boredom and loneliness. Think of your dog as a restless kid with too much time on his hands. Play dates with friends (and their dogs) work wonders. The dogs get the added attention they crave while learning social skills. Exercise is a great way for releasing pent up energy, which would otherwise be aimed at your favorite chair or pair of shoes. This does not mean the dog plays in the yard by himself. This means "together time" - long walks or playing ball so that Kahuna is neither bored nor lonely.
With commitment comes sacrifice, but the sacrifice doesn't have to be your furniture, just your time and love, and love will come back to you a thousandfold.