Dummies books are great if you are new to a topic and want to either skim it or learn enough to be able to select a more in-depth book. That is why I got this book. I am involved in a GIS project with the Red Cross that uses Google Earth and I wanted to quickly come up to speed on the product and have enough knowledge to 1. get started working on the project and 2. intelligently select a more in-depth book. As usual, this Dummies book filled the bill.