Thanks for the picture of him, he is a Congo African grey. There are two types of African Grey Parrots, Congo and Timneh. He looks great!
He may be a bit territorial about his cage and/or things that he has claimed as his. Don't offer him food all spread out on your hand, use a dish to offer food that way, or even on a piece of cardboard. hold food between thumb and finger with fingers aligned so that when his beak closes on food it would close between thumb and finger so that you don't accidently get bit' It is always better to avoid bites than to try to train biting out of him.
Read this, try it out and let me know how it goes, ok?
viewtopic.php?f=11&t=227 It is about training your bird to Step Up and Targeting. Hope you like it.