Dogs and kids - it's as American as apple pie and ice cream. In MOST cases, it's a perfect combination, but parents must be careful to teach their children a few simple safety rules to make sure the encounter doesn't end in tragedy:

0. ALWAYS ask the dog's owner if you may pet the dog. The dog may be "working" or may not be familiar with little children or strangers.
0. Approach the dog from the front or side slowly and calmly. NEVER surprise a dog from behind or force him into a corner.
0. Don't try to touch a dog when he is eating or try to take the food away.
0. NEVER take a toy away from a dog unless he is trained to drop it or give it to you.
0. Avoid teasing, tug-of-war or wrestling - the dog may forget that you are not another dog.
0. Don't stick your hand inside a strange dog's crate or through the fence of his yard - dogs naturally protect their space.
0. If two dogs are fighting, call a grownup.  If you get in the middle, they might turn on you instead.
0. Watch how a dog is reacting. If he growls, barks or shows his teeth, say "NO" and walk away slowly with your arms at your sides. Do not go near a dog if his ears are back or the hair on his back is standing up.
0. If a dog does any of the things above, do NOT scream or run or stare into his eyes.