It's eaaasy. Just be consistent, take the dog out every 2 hours or so during the day. Keep it in a cage at night, one that isn't too big. That way they will cry and try to get your attention before they will want to sleep on their pee/poop. It's how they learn to tell you they have to go out, otherwise you'll have a dog that knows to go outside, but doesn't know how to tell you.
You could get one of these, and make the dog press it everytime you take it outside so it has more options.
http://www.comforthouse.com/doorbells.html
My dog knew all the basic commands before he stopped going in the house too, but he had a confusing puppyhood..being at work in an inside/outside environment. Now he knows the name of everyone of his toys, rooms of the house, objects (tv, computer, etc), some people, favorite places (farm, beach, park, etc..), tasks, etc... Fast learner.