Some of us learn software sitting down with a book in front of a PC. Others learn by trial-and-error, working things out in front of a PC with occasional references to on-line documentation. I'm of the former persuasion, probably because I'm an old geezer.
So I happily inform you that we finally we have a book for learning the latest version of QGIS: Learning QGIS 2.0. Published in September 2013 by Packt Publishing, the author is Anita Graser of the "Free and Open Source GIS Ramblings" blog fame. She is a QGIS developer, as well as a prolific contributer of QGIS related tutorials and blog articles.
You can order it directly from the publisher, or from resellers like Amazon.com. Buying from the publisher gives you a choice of buying the print version or the electronic versions, or both. At this point, Amazon, while offering a lower price for the print edition, doesn't give you the option of buying the various electronic versions of the book.