No dog is completely childproof, even a Golden Retriever. Although Hollywood and television often portray dogs with human thoughts, values and even words, it is important to remember that your dog is a dog, not a person.
Dogs have different needs than humans do.
One important element in a dog's life is his need for a pack hierarchy. The first thing you must do to assume leadership with your dog is take your dog to obedience school. An ill behaved dog is a threat to your children, plain and simple. You cannot control your dog around your children if he doesn't know or won't obey basic obedience commands. Include your children in setting these rules so that they know what the dog is allowed to do and what it is not.