Seriously, though, coming from a farm, I've learned that some animals just won't learn unless they are shown what's right and wrong with a bit of physical force...I know I might get half the site against me for this, but seriously, most dogs just won't learn, no matter HOW many times you say "NO!!". Dogs don't speak english.
And I'm not saying, beat your dog senseless or torture it senselessly. I find that cruel and completely unecessary. But, a little tap to show that biting people will result in punishment, they will learn not to do it. Tap harder if you see no improvement.
Don't make a habit of this, though...and remember to reward the dog for things it did do right. Otherwise it will just live in fear of doing everything wrong and be very confused...
LoL He's got a point I've have two little dogs here and when we first got them they did nothing but be a pain, so tapping them on the back (only lightly as they are only small) told them that they were doin wrong and of course we always give them treats when their good
now their (mostly ) good dogs so I suggest do that