We were lucky, ours was immediately housebroken. The first time he spotted our couch, he tried to claim it. We said "no" and took him outside. He never tried to mark again.
When he has to go out, he goes to the door and gives a little whine, or if we don't hear him, he will bark at the door to the back yard.
In the three years he has lived with us, Jake has had a total of 1 accident in the house when someone shut the door to the gameroom and forgot he was there.