Jimmydr
"The Doberman is a loving, protective family dog if given the proper socialization and training. However, this bold and smart dog is bred to be dominant and will quickly assert itself over you if given the opportunity. The secret to a sweet, docile Doberman is firm but friendly handling. Socialize your Doberman at 12 weeks of age to be with other dogs, pets and people. This will prevent your dog from becoming too overprotective of his family and will assist him in developing an even temper.
Be firm and consistent when training your Doberman. Training should begin when your dog is a puppy. Also, the entire family should learn how to handle your Doberman, as these dogs will take control if they sense weakness or hesitation in their owners."
You should search the web for info, I did when I wanted a dog for my kid and for protection, and found that Boxers where best for kids!