Reinforcement can be anything your dog likes. Most people use small pieces of a “high value” food for training treats — something special — such as dried liver or even just their kibble. Lavish praise or the chance to play with a favorite toy can also be used as a reward. Dogs must be taught to like praise. If you give the dog a treat while saying “Good dog!” in a happy voice, he will learn that praise is a good thing and can be a reward. Some dogs also enjoy petting. Food is often the most convenient way to reinforce behavior.
Discourage him from biting or nipping. Instead of scolding him, a great way to put off your mouthy canine is to pretend that you're in great pain when he's biting or nipping you. He'll be so surprised he's likely to stop immediately. If this doesn't work, try trading a chew toy for your hand or pant leg. The swap trick also works when he's into your favorite shoes. He'll prefer a toy or bone anyway. If all else fails, break up the biting behavior, and then just ignore him.
It typically takes 4-6 months for a puppy to be fully house trained, but some puppies may take up to a year. Size can be a predictor. For instance, smaller breeds have smaller bladders and higher metabolisms and require more frequent trips outside. Your puppy's previous living conditions are another predictor. You may find that you need to help your puppy break old habits in order to establish more desirable ones.