Dogs bark. It's what they do. No matter what the breed though, for most families, excessive or prolonged barking needs to be corrected. Here are some tips to decrease barking:
Exercise! An exercised dog means that he will have less energy to bark with. Additionally, walks around the neighborhood or park will have the added benefits of socialization for many dogs.
Socialization! Most dogs are barking at things that startle, scare, or excite them. With proper socialization
, the things that fall under those categories should be few and far between.
Reward quiet. Heavily. Frequently. With great, yummy, sticky/chewy (so they cant go right back to barking) treats.
Do NOT let them practice the behavior. For instance, if they bark at the mailman when he passes by the window, do not let them sit looking out the window when the mailman comes by. Barking is frequently reinforced by the environment (i.e. the reinforcement is out of your control) so it's best to manage them so they cannot practice unwanted barking.
If they are barking for attention, ignore them. Any yelling, attention, or giving in to the "demands" will be reinforcing the barking. I will warn you that if you ignore them the barking will get worse before it gets better.
Do not give the dog what he wants when barking. This sounds like a no-brainer, but if a scared dog is barking at someone that comes over and you put him away, he got what he wanted (distance from the scary stranger). A better bet would be to put him away before the scary thing appears or try to get him to quiet down before he is put away. Putting him in another room is not a "punishment" if he wants to get away from the scary thing. Likewise, if he is excited to see someone and is barking, do not let him greet the person just to get him to quiet down. Wait until he is quiet THEN let him greet.
For a dog that barks at the front door when the bell rings or someone knocks, practice rewarding for quiet immediately after ringing the bell. This will require great treats and being right next to the dog so he can be rewarded before he beings to bark (you have to be FAST!). If it's desirable to have the dog bark when the bell rings, then you just decide how many barks are acceptable then interrupt and reward heavily after the desired number of barks. That will teach the dog it's okay to bark, say, 3 times and the treats will keep him from continuing to bark.
If the problem is that the dog barks at another family dog while playing, you'll need to separate the barker as "punishment" for barking. For example, if Fido barks at Fluffy, you would immediately correct him with a verbal "eh-eh" or (something like it), and then remove him from Fluffy for 30 or so seconds. He should quickly learn that he only gets to keep playing if he remains quiet. For this to be effective though, every bark must be corrected every time.
If the dog is prone to outbursts and appears "on edge" and reactive, steps should be taken to reduce the dog's stress level. Dogs need a couple of days, at least, for the stress hormones to return to a normal level after a particularly exciting event. If the dog is reacting on a daily basis to something, he never has the opportunity to truly calm down. An example of this that happens to many people, is when you have a near miss accident on the freeway. For a little while afterward, you may be very jumpy if another car gets close to the line or seems to be too close to your side of the road. Dogs are the same way.