There are as many reasons for a dog to bark as there are things for him/her to bark at. Its also a very natural act, common to all dogs. Thus, only when it becomes excessive  it evolves to a problem. To stop dog barking, first you have to find out why she's barking. For some dogs, barking is triggered by the doorbell, a passing car, or other common sound. Often this behavior can go on for quite a while.

Try a simple little homemade device called a shake can to curb your dog's barking. It's safe for the dog, easy to make, and often works like a charm.Take an empty aluminum soda can, put a few pennies inside, and tape the top shut. When unwanted or excessive barking happens, toss the shake can in the direction of -- not at -- the dog. Do not try to hit her with it. The sudden loud rattling noise is often enough to surprise her into silence. This is your cue to jump in and tell her what a good dog she is now. Try to work it so the shake can appears to come out of nowhere. This way, your dog will connect you with good things (praise) and the shake can with bad things (barking). If your dog/puppy is barking for attention, you can handle the situation two ways. The first is to ignore him/her until he/she stops barking. Don't pet her or yell at her. When she finally stops, praise her for being quiet. The alternative is to give the dog more attention than she wanted. As soon as your dog starts barking, put a leash on her and take her through a routine of sits, downs, comes, and stays. Continue this for a couple of minutes, then just walk away. Your dog will soon learn the sound of silence gets her the attention he/she wants.

Courtesy Howstuffworks.com

IDENTIFY WHY YOUR DOG BARKS EXCESSIVELY

THERE ARE MANY REASONS WHY DOGS BARK

• Isolation
  
  
• Being Confined (Behind a barrier, in his kennel)
  
  
• While they're playing
  
  
• Barking at other animals
  
  
• Need of Attention
  
  
• Separation from Pack or Familiar Surroundings
  
  
• To Alert others, (or you) of Danger
  
  
• Simply for Fun

STOP DOG BARKING TIPS

Prevent inadvertently rewarding your dog for barking. This may happen in many ways. Comforting, treating or cuddling them to make them stop. This actually encourages this behavior an makes the dog assume that you are pleased by his/her actions.

Shouting at them, Since dogs will always be dogs, and do not understand English (or whatever language u speak)so they just might assume that you are joining in, even trying to play.

Having them use barking to get their way, Some dogs bark when they are hungry, thirsty, wanting to be released from their cage or to be let inside.

De-sensitize your dogs from what triggers their barking

De-sensitizing basically means diverting their attention during the occurrence of the trigger, Eg. Doorbell, Phone rings, Vacuum. Review the scenarios below.

Barking at the Doorbell

Doing this requires artificially setting up the particular scenarios that causes barking.

• Telephone Ringing
  • Call your phone from your cell phone a couple times, you can either ignore it by doing nothing, continuing to  repeat until your dog realizes its not a big deal and gives up.
  • Also you can have some of his favorite treats handy, the second the phone rings you give him/her a treat, be sure to keep his attention on you. Do this until he associates the "telephone ring" with him/her getting a treat.

• Doorbell Ringing
  
  The same process would apply, the goal is to have your dog associate these sounds with an event with which you have control. Have your spouse and kids ring the doorbell on your mark, keep your dogs/puppies attention on you, by giving him/her a treat the second the sound occurs.

Barking for Attention

Barking At Passers By

Barking at passers by is a very difficult problem to stop. The reason being, its not really a scenario you can easily set up artificially. Also your dog considers passers by or visitors (mailmen, Garbage men) to be threats, and is rewarded every time the "threat" is averted by them leaving. Therefore, the most effective way to deal with this behavior would be to have your dog properly obedience trained. This will make it simple for you to consistently communicate to him that this is unacceptable behavior. Otherwise another method would be to block his view of the street or the window, which would only be a temporary fix and much unwanted hassle. Lastly If your dog keeps barking at the same person, maybe a friend that comes over or the mailman, a solution could be to have a talk to them and have them give your dog one of his favorite treats so that the visits or passes by of these individuals would be more pleasing to him than a threat.