Choosing the right dog for you and your family can be a challenge. While no dog's personality is set entirely by their breed, dog breeds do have a lot to do with their disposition and tendency toward certain behaviors. With many dogs, there is a very difficult balance of nature and nurture, and it's important to recognize that balance when choosing your own pet.
The first thing to understand is that dog breeds are not accidental products of evolution like so many other species and sub-species of animal. In most cases, dogs were bred in certain ways for a purpose, one that was determined by the needs and desires of the people doing the breeding at the time. That is not to say that every appearance related trait was chosen by somebody at one point, but rather that by picking dogs that exhibited certain desirable traits, many of the dog breeds that we know today were engineered to move and act in certain ways by primitive human beings thousands of years ago.
That means that if you're looking for a dog that is going to play with young children, you don't want a breed that is known for being calm and unflappable. Similarly, if you're looking for a work dog to help out around a family farm as well as be a pet, then it's important to choose a breed that has a tendency toward directed activity. Here are a few breeds you might want to consider for various purposes.
1. American Pit Bull Terrier - Many people hear the words "pit bull" and immediately get frightened. And that's not unreasonable since many of them look very scary. That being said, the American Pit Bull Terrier is one of the most loyal and friendly dogs you're likely to encounter. They can be fiercely protective of their owners and extremely affectionate to the people they are familiar with, and they usually love to play, even well into their age.
2. Beagle - There was a time when the Beagle was the most popular dog in the US. While this probably had very little to do with Snoopy, it could certainly be attributed to their calm disposition. These are dogs that like to relax and generally aren't the kind to run around and jump all day. They are part of the Hound category and were originally bred to be hunting dogs, which is one of the reasons why they have such highly developed senses of smell and tracking ability.
3. Labrador Retriever - Originally bred in Canada, these are currently among the most popular dogs in the United States. They are not only very loyal and affectionate, they are known to be also remarkably intelligent. The Lab is one of the better family dogs for that exact reason, since it will not only be great with kids at play, but has the mental facilities to know how to stay safe with them.
4. Dachshund - This was originally a German breed and designed to be a scent hound. That's one of the reasons why Dachshunds have short legs that bring them closer to the ground and long, highly developed noses. This particular breed was developed to dig in badger holes and find game, so they tend to be very energetic and love to find and chase. Often you'll find them with their nose to the ground, sniffing their way through life.
5. English Bulldog - Among the noblest of dog breeds, the English Bulldog makes up for their strange, disproportionate look with stature and gumption. The Bulldog is often considered lazy because they sleep quite a lot, but one thing that can be said about this dog is that they are also stalwart protectors of their families, with an intimidating, stocky frame that supports an oversized head and undersized arms. If you plan to go swimming, though, don't bring your Bulldog since their body proportions make it difficult or impossible to keep their heads above water.
There are only some of the dog breeds you may want to check out. If you're interested in breeding yourself, take a look at the American Kennel Club's Dog Breeding Guide and their guide to buying a purebred dog.