Sean, The Martian Chronicles is an easy book for kids, but also hard. It uses lots of styles and genres to tell its many short stories. These stories are all a little different, in part, since Bradbury wrote them at different times and for the scifi magazines that were the main place to publish scifi. So, The Martian Chronicles is really a collection of short stories around an idea: the colonization of Mars by humans.
Here are some links that might help you develop a deeper appreciation for the book:
http://www.raybradbury.com/articles_lamonintor.htmlhttp://www.wsu.edu:8080/~brians/science_fiction/martian_chronicles.htmlhttp://www.scifi.com/set/playhouse/martian/http://www.raybradbury.com/articles_nyt_mag.htmlhttp://www.raybradbury.com/articles_county.html