There is a downside when you adopt a dog from a shelter. You know less about the dog than when you adopt from a private rescue or buy from a breeder. If the dog is a puppy, you will have no guarantee of his size or appearance as an adult. You also might not be sure of the breed or mix of breeds.
There are different types of shelters: private/nonprofit, municipal, and progressive. Private/nonprofit and progressive shelters are usually small, housing fewer animals than municipal or county-run shelters. They also may have better kennel facilities and employ a number of volunteers and staff members who work not only to feed and shelter the animals, but also to do some training, socialization, and adoption counseling. Municipal shelters usually serve as both animal control facilities and animal shelters, taking in strays and owner turn-ins as well as trying to adopt dogs out. Unfortunately, municipal shelters usually must euthanize a greater number of the dogs in their care than do private/nonprofit shelters and may be overcrowded or understaffed.
Be prepared to give information about yourself and family when adopting. While municipal shelters may only ask for basic information from you, such as your name and address, private shelters are much like breed rescue groups in their adoption process. They may ask you to fill out a lengthy application and also provide you with adoption counseling, helping to match the right dog with your family. Many shelters even have get-acquainted rooms where you can spend time with a potential pet before bringing him home. Some shelters also allow a grace period, a short period of time to keep the dog in your home before you officially adopt her to help ensure that this is a good match for everyone involved.
There are many animal lovers that prefer to adopt from municipal shelters, with the feeling that they are able to make the greatest impact there. On the other hand, some people like the support and counseling that they receive through a private shelter. You should make the decision based on your comfort level.