Fold your leash up in your hand so there are only a few inches between your hand and his collar (very short leash). Keep the collar high on his neck - right behind his ears and your hand above that. This position gives you a lot more control and he cannot bite the leash or your hand this way. From the beginning make him walk at your side this way - no sniffing or weaving or pulling ahead. If he tries to bite the leash or your hand, stop, pull up and make him sit. He should calm down and give you eye contact. When he does that praise him and continue walking. After you have a successful period of time walking with him behaving with the leash short and staying by your side, then you can give him a loose leash, let him sniff, etc. for a bit. If he starts to get naughty, shorten your leash up again, make him get in position next to you and go back to the controlled walking until he earns the loose leash again. This tells him you are the leader and sets you up for a lot more success in the future. Stay calm and determined to do it your way, not his.
This also gives him the challenge of walking next to you and concentrating on your speed and direction (walking fast will help him be more successful - it makes it more interesting for a dog). Dogs liked to be challenged -- right now he is challenging you by biting the leash and your hand. You should be the one giving him a mental challenge so that he does not resort to his ideas.
Another approach you can use instead or in conjunction -- read about clicker training (http://www.clickertraining.com
) and use the power of positive reinforcement and good timing to reward him when he is walking nicely. When he starts to act up you can respond the same as above, then continue walking once calm and in control and go back to rewarding him for his good efforts. Most dogs learn quickly with positive reinforcement.
There are many ways to train a dog. Find a style that works for you, but in any case you need to be the one making the decisions and challenging the dog, not the other way around.