Web Analytics Demystified or how to tame Web Analytics
N° 1 in my list!
Eric Peterson does a great job explaining the importance of Web Analytics applied to online business. Although he keeps it quite simple he manages to do a great job explaining the technical aspects of Web Analytics data capturing and processing.
I really enjoyed chapter 5 and how he explains the importance of content structure and naming as a fundamental aspect of actionable reports. Furthermore he clearly presents 3 approaches to this fundamental milestone of your WA implementation.
I certainly recommend reading this book and keeping it in your desk for reference.