Red Planet is an easy read. It's one of the books Heinlein wrote for young people, and as such is quite enjoyable. The plot revolves around a young man named Jim Marlowe, and his "friend" (Jim refuses to call it a pet) Willis. Willis is a Martian Roundhead, a ball of fluff that can extrude limbs at will and functions as a verbatim recorder of everything it hears. One day Willis overhears a conspiracy that threatens every colonist on Mars, prompting Jim to go on quite an adventure to warn his family and friends. A wonderful book, which introduces Martians and their society (excellent for explaining some things in Stranger in a Strange land), and should be enjoyable to all ages!