Of course proper training of the pooch is important, but for those mistakes we use Natures Miracle. It comes in a small qt size or gallon for those more frequent issues. Dry up as much as you can with paper towels, then spray or flood the area with the product. It will neutralize the odors. Using a black light in a darker room will show up the urine if need be and will show you if you removed the urine with the product as it will no longer glow green.
You should be able to get it at most pet stores and some larger food store chains in the pet isle.
Chuck, @Christine at First Home Love Life has a great post about this: http://www.hometalk.com/545977/homemade-pet-odor-eliminator-and-dog-urinating-deterrent
I have cats, but never had this problem. I'm guessing dogs can be cleaned in the same manner. This is what I do: http://www.howtocleanthings.com/pets/how-to-clean-cat-urine.htm
@Chuck nichter we had this problem with one of our dogs. The trick is to try and treat it as soon as possible. We would soak the area with vinegar and then cover that area with baking soda. Let dry then vacuum. They also have pet uring cleaning products on the market. We also blocked the dog from carpeted areas with babygates and a board through the stair rungs. Of course getting them outside regularly and giving a treat when they are successful helps a lot too. Our current dog knows the word pee and complies when we tell him what his business is LOL
Citrus Magic has a product that works better than Anything I have ever used...even Natures Miracle. It's called Pet Odor Eliminator and you can do a search for Citrus Magic and find it. I bought it by the gallon when I was doing end-of-life-care. I used it in the wash and it took about a Tablespoon is all. Also used it on the carpet when we had a cath bag leak. Natures Miracle didn't work at all and involved way too much work.