Semantic Web For Dummies
Jeffrey T. Pollock
Wiley
Semantic Web for Dummies is a wide-ranging look at the Semantic Web (also known as Web 3.0) that will open your mind to the potential of this new era in web development.  Mr. Pollock's book is an intelligent and informative explanation of this software technology. Although not an in-depth programming book - it provides an excellent overview of the salient features of Web 3.0. First off, while I, too, am an Oracle employee, as is Mr. Pollock, I have never met him or communicated with him in any way. 

I had previously read a couple of articles on the subject but didn't really see the big picture and felt pretty clueless as to what it exactly is and why it matters (definition of a "dummy", I guess); so l was looking for a single source to stitch it all together and get me started on the semantic web journey. This book fits the bill nicely. Pollock arms you with a solid understanding of what core technologies make up the Semantic Web.
As Pollock explains, key to understanding what differentiates the Semantic Web from previous web development is that it creates a "data web"; i.e., webs of data that are interconnected, accessible and logically analyzable and, thus, of benefit to users. That's really the "why" of the semantic web.  
Semantic Web for Dummies includes chapters on the core "languages",  RDF (Resource Description Framework) and OWL (Web Ontology Language); other chapters explain metadata and ontologies. Part IV, entitled, "Putting the Semantic Web to Work" brings the Semantic Web's utility into the business world touching on enterprise and software development issues including the key aspect of building a knowledge-base incorporating both system management and security issues. Proving he understands the implementation risks facing any implementer using new technology, Pollock also provides a chapter outlining the limitations of the Semantic Web for business development. The book points you to both open source and proprietary semantic tools and current web sites using semantic technologies. 
 
I'd say that after reading this book, I'm not a Semantic Web expert, but I'm no longer a dummy.