The all important stain free carpet! House training is one of the most telltale signs of a well trained dog is whether or not they relieve themselves inside or outside. House training is one of the simplest things to do, yet some people really have a problem with it. It has NOTHING to do with the dog, and everything to do with YOU! Training a dog to go to the bathroom outside is all about GETTING THEM OUTSIDE! You have to watch your puppy like a hawk, and be PROACTIVE! When you have a puppy you have to always have your eye on them, its just like having a kid, you have to be VIGILANT!
The easiest way to do it when you have a puppy is to take them outside EVERY 15 MINUTES!
Especially after eating or drinking anything, puppies pass food and water through their system very fast! Every time you go outside you need to encourage your baby, and use you command for "Bathroom" and say good boy/girl very excitedly before, during, and after they do their business. So when you go outside, you're saying "(Maximus) Bathroom, Go to Bathroom" as soon as they start going "Good boy, Bathroom! Good boy Bathroom!" and even clap and cheer for them, I still do this! Then when they are done, have a treat ready for them, give it to them and say, "Good boy, you went to the bathroom!" and rub/pet them super lovingly! This will make it so that they love the attention the get for going to the bathroom outside!
You need to learn your dog's body language! You need to watch your dog's every move. When you see them about to go in the house, that is the best time and way to ruin any want they have to go inside again. If you catch them in the act, the best way to deter them from finishing/doing it again is by making a really loud scary noise/yelling BAD BOY!, to freak them out, immediately get them to stop what they are doing, and create a negative association with going inside. That way they will think twice before going inside again because they will not want to have the willies scared out of them! Now, immediately after catching them in the act and yelling/screaming/stomping towards them, you have to grab them and run them outside and immediately begin the "Go to the Bathroom" command, and cheer them on to finish what they started, but correctly outside! Then after they do, again be very happy and clap for them and give them lots of love. That way they will see the huge difference between going inside and going outside. Any smart dog will want the positive reaction rather than the negative.
A lot of people will tell you that you should hit the dog, or put its face in the mess or whatever. I wouldn't say I necessarily agree with that, especially hitting the dog. A little rap on the nose and a "Bad Boy!" is okay, but you don't need to lay into the dog, that doesn't do anything. Then the dog will also begin to associate "Good Boy!" with being good, and "Bad Boy!" with being bad. Just make sure that you immediately go outside and give them the chance to do the right thing, putting them outside shows them that's where it was supposed to be done.
If you want to do something about where they went inside, one thing that I learned to get them to not go back to the spot they just soiled is by taking a little bit of Tabasco sauce (careful because it does stain, and a little bit goes a long way in a dog's nose!) on the spot where they went, and then also putting a little in their mouth (here you can use a little more if you want ;). Believe me they won't want to go inside again! I also use this Tabasco trick for things that he shouldn't be chewing on, like the wooden legs of a recliner! A little on the wood, and in his mouth, and tell him, "Not Yours!" no more chewing! Also another chewing deterrent is making sure that they have plenty of things that they can chew on, TOYS!