Advanced Web Metrics with Google Analytics by Brian Clifton is the book on Google Analytics I wish I had two years ago (but he had not written it yet) and it's the one book I'd own if I was serious about using Google Analytics for anything beyond it's out of the box capabilities - I wrote my detailed review in a post titled Advanced Web Metrics with Google Analytics Review at TheAnalyticsGuru.com.
I'm starting to get so many books to review - it takes time to read a book closely enough to have an informed opinion - I won't say I tried every single thing Brian Clifton wrote about in Advanced Web Metrics with Google Analytics, but I have run into enough of the problems he mentions, plus many that I have not yet run into but probably will, at some point, to know the value of the information he's collected in this book.
I look at advanced Web Metrics with Google Analytics by Brian Clifton as one book you'd really want to have if you use Google Analytics at all. To his credit, Brian did more than talk about Google Analytics - he also talked about how work with stakeholders, what reports to run to answer their questions - how to best implement Google Analytics in your company or personal framework and the best ways to track conversions (it's not always about Goals, sometimes, it's about using the Commerce Tracking capabilities, instead, especially if you have a lot of items to track - like individual books that are downloaded several times - you would not want or would not be able to have a Goal for each book or item downloaded).
I want to point out that while I was happy to receive a review copy of Advanced Web Metrics with Google Analytics by Brian Clifton - I did not ask for a copy beforehand and have no association with the author. The reason I am writing an glowing review of Advanced Web Metrics is the quality of the information within.
You can get more of the details (and it helps to have a copy of the book to review what I noted about it) in my full Advanced Web Metrics with Google Analytics Review.