First, the bad news: your puppy isn't going to sleep through the night at first. Like having a baby of your own, getting a new puppy is a commitment to sleepless nights for a while. When everyone else is in bed, the house is dark, there's nothing interesting going on anywhere and your puppy feels isolated, so she'll bark and howl. The good news is this generally lasts only for three or four months, and you can expedite it with appropriate measures to teach your puppy to sleep through the night.
Refrain from feeding your puppy or giving her water in the few hours before bedtime. While she won't be able to go all night without a trip to the bathroom at first anyway, giving her food and drink before bed makes it more urgent and may necessitate multiple overnight trips out. When she has to relieve herself, she'll bark and howl. Take her out to her potty place right before bed, too.
Keep your puppy awake in the evening. Puppies like to sleep a lot. If yours sleeps away the early evening hours, she'll be full of energy at night, when all you want is to get some sleep. Play with your puppy in the evening, take her out for a walk and provide an extra toy or two to keep her stimulated and awake. This also helps tire her out for bedtime so she won't be up barking and howling, looking for attention and an outlet for her energy.
Confine your puppy to a crate at bedtime and let her sleep in your bedroom. Crating is comforting to your new puppy, and she'll bark and howl less if she doesn't feel completely alone. If you don't want to get your puppy accustomed to sleeping in your room, crate her elsewhere and leave something on that makes a little noise. Play some music quietly, leave a fan blowing or try a white noise machine. Remember, from a distance, you'll have to be extra attentive for signs your puppy needs to go out to relieve herself.
Prepare for overnight potty trips before you go to bed. Your leash, flashlight, slippers, a plastic baggie and anything else you need should be readily accessible, so you don't have to go searching for them in the middle of the night. The less your puppy moves around and gets stimulated, the better the chance she'll go back to sleep instead of starting to bark and howl when you put her back to bed. For this reason, don't reward her as you do during the day when she adheres to her housebreaking training. Try not to talk to her and don't pay her attention. Take her right to the potty and then right back to bed. Go directly back to bed yourself.
Ignore your puppy's nighttime barking and howling when you know it's not a signal that she needs to go out to the bathroom. If you go to her or pay attention to her in response to her noise, you'll only teach her that this behavior works, reinforcing it. Yelling at her or punishing her won't get her to stop, either. It will only wind her up more and interfere with bonding between the two of you.
Eric Mohrman has been a freelance writer since 2007, focusing on travel, food and lifestyle stories. His creative writing is also widely published. He lives in Orlando, Florida.