Many people swear by crating the puppy. They don't like to mess where they sleep.
I have always had great luck with frequent outside trips and over the top praise when ever they do the potty outside. In fact my current dog is now 12 and I still to this day praise her when she does her business outside and she has been potty trained since she was a baby. It has been a long time since I trained her though so I can't remember how old she was, I do remember she learned quick.
The dog before OMG he was awful to train. In fact he was so bad I trained him to not walk anywhere in the house that was carpeted. He learned that pretty quick so cleaning up messes was tons easier. Maybe about a month after learning "off the rug" he finally grasped to pee outside. But the off the rug training stuck as well so it was a godsend when bringing him inside on rainy muddypaws days.