This book gives a really good introduction to WordPress and it will be useful for anyone wanting to use WordPress for blog production or as a content management system for producing a static web site. Like other books in the Dummies series, it explains topics in a way that can be read by non-techies, but there's plenty there for people coming from a dreamweaver/html/css background, especially when it delves into tweaking existing Themes, towards the end of the book.
Committed techies might also want an additional book for more detail on production of their own themes, plugins and other stuff, but this book will still be useful as an overview and quick reference.
I've used it to produce three blog sites and found it very useful.