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.
Help him relax when he comes home. When your puppy gets home, give him a warm hot water bottle and put a ticking clock near his sleeping area. This imitates the heat and heartbeat of his litter mates and will soothe him in his new environment. This may be even more important for a new dog from a busy, loud shelter who's had a rough time early on. Whatever you can do to help him get comfortable in his new home will be good for both of you.
Never leave a puppy in his crate all day; he needs several bathroom breaks, as well as play and feeding times. Even though he won’t want to soil his sleeping area, if he is in there for extremely long stretches, he just might. (He can’t help it!) And if he does, it is because his owner has neglected his responsibility, not because the dog has misbehaved.
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.
Submissive urination is a normal way for your puppy to demonstrate submissive behavior. Even a dog that is otherwise housetrained may leave dribbles and puddles of urine at your feet when greeting you. Excitement urination with a puppy is usually caused by lack of bladder control. The puppy is not aware that he is urinating; he's just excited and any punishment will only confuse him.