Athletes
These guys can run and run and run. A lot of training needs to happen before they can be trusted off leash - if they can be trusted. Expect to spend more than an hour a day outside, especially during the first couple of years. If a sled dog is bored or restless with unsupervised access to your stuff, chewing can (okay, will) be a problem. Using a crate is an excellent preventative measure.
Independent
They think for themselves and act on their own best instincts. This is another trait that renders a lead mandatory! Loving but not doting, these are interesting and entertaining companions for people that want to be loved but not fawned over.
Diggers
The instincts in these breeds are close to the surface. They know how to take care of themselves. Digging a shallow pit under a shady bush is a great way to stay cool. Few of these dogs can resist such a sensible approach to comfort.
Howlers and "Talkers"
Expect to hear a happy "Ouuuooo" when your dog greets you. If left alone, they may well howl. Most are not especially barky.
Predatory
Hunter's blood courses through many of their veins and many will chase after, and some will dispatch, smaller animals if allowed to. They can usually be taught to respect other pets in the house, but not always outside.
Common Problems: Digging, Destructive Chewing, Howling, Housebreaking, Dog Fighting, Olympic Leash Pulling, Predatory Behavior, Dog Fighting, and Running Off.
The Good Home: Easy-going, active people who want an athletic, fun companion who doesn't hang on their every word. Great for joggers and hikers. People who enjoy bright dogs with a wicked sense of humor should enjoy this group. If you can't bring yourself to use a crate, don't get a sled dog. You must be tolerant of hair in vast quantities during the twice a year shedding periods.