Having not thoroughly used the CiviCRM interface since CiviCRM 2, it's easy to get lost in all the new features. Being a CiviCRM extension developer, getting lost stinks.
Now instead of feeling my way around blind, I have a great guide to the interface. It's not just simple interface usage mind you, yes it does cover the basics that the end user / client admin might use, but also dives into the really advanced interfaces in Civi.
This really is a great book for CiviCRM users (or developers) at any level because Civi is always on the move and I find it easy to get left in the dust regarding the UI, even if I can code the next cool payment processor integration for it.
The book on Packt: http://link.packtpub.com/BsCpiD