The prime directive of housetraining is to prevent your pup from making mistakes. The first time your pup soils in your house it creates a precedent. Subsequent mistakes quickly reinforce that mistake. At this point however you've probably had your pup for a while and he probably has already made many mistakes in the house. Now you have your work cut out for you because not only do you have to show your pup where the appropriate place to go is you also now have to break that already bad habit that has formed of going in the house.
Whether housebreaking a new puppy or resolving an existing problem in an older puppy, the 3-step routine is the same:
Prevent your dog from making mistakes in the first place. Meaning keep an eye on him at all times. Put a leash on him and make him follow you around in the house or if that is not feasible crate him when you are not playing with him. Only after he has eliminated allow him free access in your home.
Show your dog the appropriate area to go by taking him to that place. Don't just open the door and assume he knows what to do-go with him and give him the command "Go Pee Pee" or whatever commands you are using. Eventually he will figure out what this command means and will start to go on demand.
Reward your pup for using the appropriate toilet area with a huge amount of praise and a favorite cookie.
Crate training is the easiest, fastest way to housetrain your dog. Most dogs will not eliminate in their sleeping area. Put your pup in his crate for the evening with the door shut and first thing in the morning when you take him out, take him directly to the appropriate area and say your command and then when he goes PRAISE and TREAT. Then take your pup inside and give him his breakfast. If your pup does not go within 5 minutes of being outside first thing in the morning, take him back inside and pop him in his crate for 5 minutes and try again. You want to show your pup that this is a business call and he is not out to play so he needs to hurry up. IF he does not go in the allotted 5-minutes keep on taking him back and putting him into the crate for 5 - minutes and then taking him out again. He will eventually get it that he better go when outside. IF you go with him every time and praise and treat he will eventually get the idea of what you want.
The most likely times your pup has to go are 20 minutes after he finishes eating, whenever he awakes from a nap, and right after a play session. The younger the puppy the more they have to go-every couple of hours. Most puppies can hold it during the night for about 6 to 7 hours in a crate but don't ask any more of them than that, provided they are taken out just before they go to bed.
If you catch your pup in the act of starting to go inside the house don't yell NO but rather say in an authoritative voice OUTSIDE and quickly pick him up and take him outside to the place you want him to go and start saying your command word. If you do not catch your pup in the act but see that he has in fact gone inside the house, NEVER reprimand him or rub his face in it. The time delay between when he went and you finding it makes it impossible for your pup to comprehend the connection between the crime and punishment. He will have no idea what he is being punished for. Instead, reprimand yourself because it was ultimately your mistake for not sufficiently confining him or supervising him. All dogs want to do the right thing so bite the bullet and take the time to really show your pup where you want him to go and be overly dramatic in your praise so there is no mistake in your pups mind where he is to go. Housetraining is a lot of work but the pay off is worth it. Dogs don't go in the house to spite their owners, Cats do I think, but dogs don't, so if your pup is still making mistakes in the house you were not clear enough in your training. House training usually takes a few weeks with most pups, so have patience and remember even though they are dogs they are still babies.