I cannot recommend a dog for people who work all day. Dogs are sociable (pack) animals who need ongoing companionship. Dogs left alone for more than 4 or 5 hours during the day become lonely, bored, and unhappy, and are likely to chew things up and bother the neighbors with their barking.

Puppies, especially, need someone home all day. Otherwise you'd have to cage or pen them for their own safety and the safety of your home, and caging or penning all day is cruel. Puppies are loaded with energy and eager to explore and learn -- all through the day. Puppy training moments occur on the fly, and someone needs to be there to take advantage of those quick (often 1- or 2-minute) opportunities. Finally, puppies left alone become stir crazy and get so excited when they finally see someone that they tend to grow into hyperactive adults.

There's just no getting around the fact that dogs are not solitary creatures -- they only thrive when given a great deal of companionship by their human caregivers.