Your questions

Do they bark a lot?

No. However, Bostons make excellent watch dogs. They take pride in defending their masters. They are fearless, often attacking a dog much larger than themselves.

Do they dig? Can I leave them outside in the backyard?

Yes, most dogs do. They love to bury their bones, toys, etc. They can be left outside for short periods. Due to the short muzzles, they can not survive outside during the summer/winter months.

Do they shed?

Yes, however, regular brushing and bathing will take care of this problem.

Are they good with children?

Yes. If they are raised with a child, they will usually become that child's protector and babysitter. Just remember, children have to be taught how to handle a young puppy.

Would a puppy or an adult dog be better?

This depends on a lot of different things. For young children, I would have to recommand an older puppy or grown dog. One that can get away from the children, if the dog will be left alone with the children for any length of time. Many times, an elderly person would rather have an older dog -- one that does not require as much physical activity, etc. Remember, think about this before you add a dog to your household. How much time you have to spend with this dog or puppy? Are you willing to take the time to housetrain? Are your children ready to help handle the responsibility for a pet? Can you handle the extra expense of a dog?

What kind of activities do they like? Walking? Hiking? Obedience? Agility? How trainable are they?

If people are involved, Bostons usually love to participate. They love long walks, hiking, etc. Bostons do have a stubborn streak, but are very trainable and love obedience.

How long do they live?

Bostons have an average life span of 10-13 years. Some longer. My oldest Boston lived to be 15.5 years of age.

How well do they get along with other dogs or pets?

Bostons get along very well with other pets. I personally have had Bostons with cats, horses, ducks, goats, and other dogs. I have also known Bostons who hated cats. This is something you hve to check on a dog-to-dog basis. Bostons usually like being the "Top Dog."

What would be some reasons I should NOT get a Boston Terrier?

They must be kept inside. They are active. They need attention and want to be played with.