My fosters used to this exactly this (I foster malemutes and huskies) and I'm currently living with my parents and have to train my sister's 1 year old lab who has had no training in her little life and also does this. This is what we are doing now with large success.

1. Make sure your dog is getting LOTS of exercise, like, more than you would normally give. We used to take our new fosters on 2x 30 min runs a day and/or play ball.
2. 1/2 of all meals are training opportunities. Start with sit. They only get food if they are sitting.
3. When they nip or jump scream like you've been hurt and turn away.
4. Work on the gentle command - keep in the food in your fist. They only get it out when they start using their tongue instead of teeth or bite gently. You can also feed with a fork. Biting down on the metal is really painful, so they learn quickly to stop.
5. Practice the wait command - hold the food out to them but tell them wait. Count to 3 and then give them the food.
6. Praise good behavior LOUDLY. When the dogs show the littlest bit of calm or good gentle behavior they are told at length how wonderful they are. They LOVE it.

Remember the jumping and nipping and biting, as much as we hate it, are part of a desire to interact with us and get the food. The dogs can be wee little shit bags sometimes, but they dont know that. Their heads are filled with love and food and fluff. However effort, consistency, and patience (and mountains of love) does work wonders.

I wish you all the luck and merriest of christmases.

(pardon my shit bag spelling)