Puppies should be confined to a safe room unless they are supervised. Puppy proof the room that your dog will be confined to. Look around the room at the dogs level and look for anything the could be a danger to your puppy. If you choose to bring your puppy to other areas of the house. Let the dog outside to do his business, first.
Puppies tend to have accidents when they get excited.
Make sure that your puppy is supervised at all times until he is house trained and obedience trained. This will do away with a lot of frustrating accidents. Think of your puppy as an infant. Supervision is the key. Puppies need to eat more often than an older dog.