You need at least some experience with preparing and delivering presentations. Even a couple of attempts to get your point across with slides will be enough. If you have never delivered any presentation in your life, you will have a hard time understanding what all the fuss is about.
Also, I don't offer much technical advice about Microsoft PowerPoint or any other application in this book. I assume that you are already familiar enough with some slide editing software. If need to improve your skills here, I suggest you read other titles from John Wiley & Sons. (PowerPoint 2010 For Dummies, for example, is an excellent book.) However, this information is important only for Part II of the book, which deals with slides. Other parts of the book that deal with structure or delivery are much more technologically independent.