Like all the Dummies books, this is a very basic introduction. This one is heavier on the concepts and very light on the actual techniques. So, it is written with beginners in mind, that is, people who really only have the faintest idea of what DM is and needs to figure out the basic concepts.
It is a little irritating that the author seems to think DM has the most relevance for business when DM techniques have farther reaching applications. Some sections are also wasted (IMO) on the strictly business stuff, as in, "executives are busy people. Don't bore them."
But again, if you look for a very basic starting point in DM, start here. But you will need many more books and classes to actually learn how to data mine.