Two terms most new dog owners hear early on are Obedience Training and Socialization.
Obedience Training is pretty self-explanatory. It's teaching your dog to obey you better. It's very important, since it helps put the humans in the position of "leader of the pack," and also helps develop control of the dog and establishment of house rules for her.
Socialization is not quite as clear most of the time. Well-socialized dogs tend to be much calmer and more adaptive to strange situations than dogs that are not given that educational advantage.
Starting at home, you can begin socializing your new dog or puppy by making a point of exposing her to new things in a non-threatening manner. For example, if you seldom wear a baseball cap, it might be a surprise to your dog the first time you do. Things that change your appearance should be introduced to the dog frequently and she should be given time to adapt to them. Wigs, masks, cowboy hats, anything that is different and makes you look strange to your dog is a step forward. It also allows her to begin to comprehend that there are different people out there.
Other things you can do would be like bouncing a basketball near the puppy. Then, let her examine it. Have some crutches lying around? Use them around the puppy and then let her examine them, too. Always encourage the puppy to examine new things, but don't force her to go near things she's reluctant to get near. Less is more in this case.
Introduce your puppy to stairs, the car, taking short trips with you, friendly people in your neighborhood. Make it all as fun as you can and praise the puppy or dog when she does well. Allow her to approach things from different angles. Sometimes, just a different angle/viewpoint of an item makes it seem totally strange to the puppy.
An example of this is when I was teaching obedience at a major pet retailer. One thing I used in my puppy classes was a child's play tunnel. It was six feet long and about two feet in diameter. Many of the puppies would be very leery of this strange thing. For some of them, we would close the tunnel totally up and let them go through it that way, then, we'd slowly let the tunnel out and encourage the puppies to go through it. One of my reluctant (at first) students even decided one day that the tunnel was a great place to just take a nap during class.
The easiest way to do this is to have two family members working with the puppy. Put the lead on the puppy (hopefully she knows what that is) and run it into the tunnel. One family member holds the puppy at one end of the tunnel and the other goes to the far end with treats and takes hold of the lead. The puppy is encouraged to come to the family member with the treats through the tunnel. Work the puppy back and forth, as this will look different from the other end to the dog. Part of what this teaches, too, is trust. Trust that you would not expose the puppy/dog to something dangerous to her.
Other socialization things you can do include handling the puppy's feet (helps with nail-clipping later), handle her tail and pat her bottom (helps her learn that her bottom is not sacred territory, especially if temps need to be taken at some point), give her a massage now and again (gives you some more control over her body and helps you know when something is wrong with muscles or in case of lumps of some sort). Teach her to be rolled from one side to another without struggling (helpful if she needs to be moved when wounded). All the time you work with her, use lots of praise and try to end all sessions on a positive note.
Once the shot schedule is complete at about 4-6 months, start taking the puppy, or dog (if an older adoption), to places like pet stores that allow pets in, shopping areas where you can have people pet the puppy while she sits nicely, visiting to "grandma's" house or other relatives'. Going to the vet's just to say "hi," dog parks where she can meet other dogs.
Use your imagination about anywhere you might ever concievably need to take the dog. The more you can expose the puppy to other people, dogs, places and activities, the more socialized the dog and the calmer and easier to live with she'll be. Besides, then she can go anywhere a well-trained, well-socialized dog is welcome and do you proud.
C. Rogers Upson has been training dogs and studying them for nearly 40 years. Her website is Dog Potentials and she has two dog-related stores at Keeping to the Borders and Dog Potentials-The Store.