At a very fundamental level, you can socialize your dog by walking him near a playground filled with children who run about, play ball or Frisbee or soccer and make a loud noise. While you
and your dog walk through a crowd of children, teach him to walk at heel and watch them play or let the kids pet him on the head. Alternatively, let him stay in the down-stay position till a game of soccer that you both are watching comes to an end. If you do this regularly, your dog will soon get accustomed to the presence and sound of children. You could also make him improve if you do the following:
Separate your kids and your dogs at snack time so that the latter don't steal food from your children's tiny hands.
Give your dog a place he can call his own, perhaps a small corner or an unused room, den or a pen in the backyard or crate.
Teach your children not to bother the dog when he is in his private retreat. Dogs can be very easily scared of high-pitched voices, stares and quick, unplanned movements—so typical of children.