Over Excitement & Chewing

Question
Our dog tends to get randomly over-excited and when this happens he pounces around the floor, jumps up, nips our legs and chews our hands. We are having problems controlling him and stopping him from doing it.

At the moment when he does it we either squirt him with water or shake a can which tends to stun him and most of the time he will calm down.

Is their anything else/better we can do to stop this behaviour?
We are worried he may do it around children and knock them over.

He is a 1 Year Old Labrador who we think is crossed with a Terrier so he is medium in size.

We got him from a rescue centre and have had him for about 8 weeks. In general he seems to be comfortable and happy.

He is beginning to take to his training i.e. he is sitting and coming back to us now.

I understand that he has been in a home before with an elderly couple and they had to give him up because he kept chewing their arms and they could not control him so we are doing our very best to stop this behaviour asap and i would appreciate any advice.  

Answer
Charlie,
The best thing to do is to immediately enroll in some basic obedience classes so they can show you how to teach your boy how to sit/stay and down etc.
The best way I've found to resolve the exact problem you mention is to teach your dog to sit.  When you are teaching sit, you tell him once and make him do it.  Always reward with a treat when he responds.   This will take a lot of patience, practice but will have good results.  You should use the "sit" everytime you give your dog attention. Unless he is sitting, he doesn't get attention (initally).  When you come into a room, you should immediately put into a sit.  If he comes to you, have him sit before you respond to him.   Sit before you feed him or walk him.   Sounds like a lot of sits, I know --- but when he learns "sit" is the key to everything, the crazy behavior should subside as he is most likely doing it for attention.  He needs to learn "sit" gets attention and not the unwanted behavior.