You don't have to be a member of Mensa to program Android applications. I'm glad, because otherwise, I wouldn't be writing them! Programming for Android is simple because the default programming language of Android is Java. Although writing Android applications is fairly easy, programming in itself can be a difficult task to conquer.
If you've never programmed before, this book may not be the best place to start. I advise that you pick up a copy of Beginning Programming with Java For Dummies, by Barry Burd (Wiley), to learn the ropes. After you have a basic understanding of Java under your belt, you should be ready to tackle this book.
Although the majority of Android is Java, small parts of the framework aren't. Android also encompasses the XML language as well as basic Apache Ant scripting for build processes. I advise you to have a basic understanding of XML before delving into this book.
If you need an introduction to XML, check out XML For Dummies, by Lucinda Dykes and Ed Tittel (Wiley).
If you already know Java and XML, congratulations — you're ahead of the curve!