Take pup out after waking up and eating every couple hours the first few days. Take the pup to the spot you want him to use. Never hit puppy or chase when it does do something wrong. Collars should be light weight and never left on when the pup is alone. Light weight chain collars are my choice in lead training.
Teething is the most critical time.
Anything you teach the pup during teething will be relate to pain. Teething usually lasts until 4-5 months of age. Check pup's bite daily to see that baby teeth are coming out. Crate training is ideal. Puppies play hard but sleep long hours.