This text presents astronomy as a case study in science. Its purpose is to help the student understand how science creates, tests, improves, or discards models of natural phenomena. It helps the student distinguish between observation and theory, evidence & conclusion.
(Taken from the Preface)
This isn't the best Astronomy textbook I've ever used, but it has the basics that you need, nice pictures, useful illustrations, and is fairly east to understand if you're far enough along in English and Math to be at the right level for it. The math equations and such are easy to spot when flipping through the sections, so finding an equation you need isn't difficult, and the layout and organization is logical and easy to follow.