Disclaimer: Please seek the help of an experienced, professional trainer who can assess your dog and the problem(s) and provide you with in person help. I am all for seeking as much information as possible, but given today's dog training atmosphere, it's more confusing & contradictory than ever! It is important that your trainer not only be experienced, but that you and your dog connect with him/her. Two organizations that can help you locate a trainer in your area are:
Learning why your dog barks is key in helping him stop the unwanted barking. Dogs bark as a way to communicate (and this can include incessant whining, howling, etc.). Rarely does a dog bark for no reason. She is trying to communicate something.
Here are some of the more common reasons dogs bark:
Boredom: What is your dog doing all day? Is he getting enough exercise and playtime with you? If he's just sitting around the house, alone, barking may be a way to vent some pent up energy. In addition to appropriate exercise and play, training new behaviors is an excellent way to mentally stimulate your dog. If your dog is alone for over 8 hours, you might want to consider a dog walker or day care a few days a week to break up the monotany.
Frustration: While some boredom barking can be attributed to frustration, dogs also get frustrated when it is unclear what is expected of them. This is usually a human problem due to inconsistency in training (poor timing, for example, which can lead to confusion). A good training class or one on one lessons can help fix this problem.
Separation Anxiety: If your dog has true separation anxiety, please consult a professional, as this is something beyond the scope of this post.
Increase or Decrease Distance: Fearful dogs will bark in order to tell you "Stay away!", other dogs bark seeking attention. While you do not want to reward the barking at that moment (since that will simply reinforce it), you do want to address the underlying fear or need for your attention.
Alert Barking: This type of barking is very familiar to most owners and usually welcome. Many owners want their dogs to alert them to people coming on their property, for example. It's when the barking doesn't stop, that there is a problem (think about the doorbell ringing, your dog charging the door barking and continuing this as you let in your friend). Training your dog to realize that the doorbell is not cause for all hell to break loose is possible! Again, please consult a trainer in your area since there are numerous ways to address this issue.
Play/Hunger: Dogs will also bark as an invitation to play either with you or another dog. Your dog also may have learned to bark or whine at you when he's hungry.
So, can you stop your dog from barking? No! That is how dogs communicate...but you can train her to stop the excessive barking in certain situations. Understanding why she barks and that not all barks mean the same thing is the first step in solving this problem. Finding a balanced, experienced trainer is the second. Good luck!