There are a lot of reasons to love London's The Call of the Wild. It is full of action and adventure, history, and a small amount of deep mythology. I know I read this as a child, since the story is simple enough that a child can understand it, but reading it now as an adult has shown me some of the deeper meanings within the same story.
Buck, a large domesticated dog (I think he is a St. Bernard mix), is stolen away from his home and sold to traders. He is taken up north to the wilderness, otherwise known as Alaska to work as a sled dog as the area booms with speculation and people from the lower states.
Once there, Buck is purchased and begins to learn the life of a sled dog. He learns to fight and survive. He learns all of those internal fighting instincts he once had and begins to thrive.
Even through good and bad masters, Buck learns to hear and understand the "call of the wild" and what it means to be a dog.
So while it seems like a simple story, there are plenty of layers. I remember that when I read the story back as a kid, I didn't really pick up on the person-aspect of the novel. Since the story is told from Buck's point of view, I only really focused on his story.
The people in the novel are an interesting part of the story. You have the people using Buck and the others dogs to deliver mail across the wilderness. There are also the naive, stupid owners who hurt the dogs from not understanding the wilderness around them, or what they should be doing in the north. You also have the wise wilderness man, who understands the value of a good dog. It is an interesting mix of many of the kinds of people who struck north during the boom of Alaska-due to gold and curiosity-back in the late 1800s.
The dogs are also a great mix. You have the old veterans, and the new pups trying to prove themselves. They are very much like a part of human society-those with more experience edging out the stupid and young.
The story also has a lot of mythology, especially when the dogs become more wild. This is something I found really grabbed me on this reading-the idea that all dogs, even your cute little chihuahua, was once a part of the wild. All of our "domesticated" animals are still animals and not like us at all. Even as I cuddle with the kitten currently curled up on my lap, I have to know that he follows his own instincts and wants, not mine (although, I think he knows how much I love to cuddle with him as well).
I definitely recommend this quick read of a book. It is valuable and entertaining and something I am sure my own future children will love.