Your puppy is bound to make mistakes, especially in the first few weeks of house training. Always remember that he is just a baby - no matter what his size and that he needs time to learn. You are his teacher, and he relies on you to make sure that he gets plenty of opportunities to do things right.
If your pup pees or poops in the house, don't yell at him. Instead, make a not to yourself to watch him more closely and take him out more frequently. Then gently put him in his crate or the safe room, and clean up the mess. Remember: reward correct behavior and ignore unwanted behavior.
Never rub his nose in the mess or swat him with a rolled up newspaper, or anything else. Not only will anger and punishment increase stress and fear in your puppy, but he'll also become sneaky about finding places to potty.
If you watch your puppy in the act of eliminating in the house, clap your hands to get his attention and, say, "Aaaaght Outside". If he stops (unlikely), take him outside to finish. Avoid saying "NO" or calling him a bad dog. You don't want him to think that the act of eliminating is wrong, you must want him to know that he chose the wrong place.
Until your pup is reliable, don't let him run free in you home. A puppy who is eliminating everywhere in the house has too much freedom. Instead, keep him by your side or confined to his safe room or crate. This is especially important during busy times of the day such as mornings and dinnertime, when you have less time to watch him. It is important to restrict his access to certain areas within the house until he starts eliminating outdoors on a regular basis.
Part of house training is being able to read your pup's cues. Dogs have different ways of letting you know when they need to go out. Some dogs bark or run to the door, but others are subtle in their communications, which they limit to staring or twitching their ears a certain way. Many dogs learn to ring a bell on the doorknob or on the wall next to the door. Be sure it's within your pup's reach. Every time you take him out for a potty run, ring the bell before you go out the door. When he rings the bell on his own, praise him and take him out. Whatever the sound of behavior, watch your pup closely to learn his signals.
If you're having problems house training your puppy, make sure you're being consistent with your training methods. Don't try method after method, quickly switching from one to another. Choose the method you want to use, and stick with it. Otherwise, your pup will become confused. Keep in mind, too, that house training accidents - specially after a pup seems reliable - may indicate a health problem. Take your puppy to a veterinarian for an exam if he suddenly breaks house training for no apparent reason. He may have a bladder or kidney infection.