Tip - Be careful with what you reinforce

When training your dog, you must be careful with what kind of behavior you reinforce. Dog's learn very simply. If your dog barks and you give him food, he will learn that barking gets food. If you keep at it, soon your dog will bark and bark till you give him food.

Instead, you should focus on making your dog do things you want, like sitting, before you give him what he wants. This way he learns its a two way street.