There are several conventional ways that people like to try and stop their dogs barking, one way is to fill a spray bottle up with water and spray their dogs when they bark. This works when in close proximity, however because the dog knows you are controlling it you do risk the dog detaching themselves from you, and not wanting to spend time with you. Another way I have heard people do is to fill a bottle up with small stones and shake this at the dog. Again similarly to the spray bottle, it only works when you are there and close enough. I have had people call and say their dogs think they are trying to play, so again perhaps not the best idea.
However, help is here at last! There are several products out there which will help with dogs barking. The first we will discover is sonic collars. The sonic collar I would recommend would be PetSafe Ultralight Sonic Anti Bark Collar. This collar would definitely be my first choice before any other type of barking product. It is perfect for smaller dogs, and it only weighs one ounce. It works by producing a loud unpleasant high frequency sonic signal which will interrupt your dogs trail of thought and stop them barking. Your dog will soon learn that when they bark, the sound is given off. This collar has a cutting edge; bark detection microphone can be adjusted to recognize your dogs own bark so no other sound will set it off other than their bark.
If your dog doesn't respond to sonic how you would have liked then from this I would recommend progressing to a spray anti barking collar. Again, this is harmless and works in a similar way to the sonic collar by interrupting your dog's trail of thoughts however sometimes dogs that are used to a loud busy household and lifestyle don't respond to sound so an action of spray will do this. I would recommend the PetSafe Deluxe Anti Bark Spray Collar. This collar has two levels of spray and has a transparent level indicator showing when your spray is almost out. It has suitable for all breeds and is lightweight and comfortable for your dog.
Finally, if your dog still does not respond to spray then the next level would be a static collar. Static collars can also be used for training such as recall issues. For this I would recommend PetSafe Remote Training Collar 250m. This enables you to control when your dog gets a static pulse. It has 8 different levels of static correction, is full waterproof, can be used on up to 3 dogs from one receiver and has a low battery indicator. It is a very high specification collar and transmitter and the quality of this product is the highest I have seen. It works by using a beep tone followed by a level of static. Soon the dog will get to know the beep tone means to stop barking and should do so to prevent from getting a static pulse. I must stress even the highest level of static on this collar is still nothing like the level of static used in electric fences. This is not a cruel way of training your dog like some people may feel. It is a training aid and from experience, it works with most dogs.