Staffy biting issue

Bit of a long story but REALLY need some help!

We have a rottweiler who is 3, female, very easygoing, no problems with people or other dogs, and a staffy who is 2, she is brilliant with people, not so great with SOME dogs, you'll know straight away if she likes another dog or not. We may be getting another staffy who needs a home for various reasons, he is beautiful, 3 years old. On the lead, he is perfect apart from a bit of pulling, but off the load, he completely changes, he jumps up (very high) at you, and he bites, HARD, it is very painful, and this is the thing that is putting us off of him. He goes for your hands, if you try and pick up his toy for you to throw, he goes for your hand, even though he has put the toy at your feet. He has not been neutered, would this make a big difference? He is a lovely dog, and deserves a good home, but when he bites, it feels like he is breaking your fingers! Any advice on the neutering or anything else that may help?

Hiya I am going to move this to training and behaviour section it will get more views. I have had no experience in this but someone will be able to help. Why not come and introduce yourself here   
https://staffy-bull-terrier.niceboard.com/f7-new-member-introductions

It sounds to be like he's never been taught any bite inhibition, I would go back to basics as if he were a puppy, these links should help  

http://staffy-bull-terrier.com/how_to_stop_your_staffie_jumping_up

http://staffy-bull-terrier.com/stop_your_staffy_puppy_biting

Would agree with Sazzle above, go back to basics and start a fresh with all the training.

Sazzle wrote:It sounds to be like he's never been taught any bite inhibition, I would go back to basics as if he were a puppy, these links should help  

http://staffy-bull-terrier.com/how_to_stop_your_staffie_jumping_up

http://staffy-bull-terrier.com/stop_your_staffy_puppy_biting

The advice in the links is excellent. Just remember the change doesn't happen overnight and everyone that interacts with the dog has to consistantely follow the advice.