Practical Vim: Edit text at the speed of Thought is an intermediate to advanced book on Vim published by The Pragmatic Bookshelf. I found this a very useful Vim resource to sharpen my skills. In this post some more feedback on the book.
(Disclaimer: I received a copy of Practical Vim for review)
This book teaches a lot of Vim skills in 121 tips. Some are easy, others advanced, but above all they teach the Vim way! Following the examples you start to approach text edit challenges differently. Even feeling comfortable with most editing tasks, there is probably a better way to do it. This book had quite a few eye-openers for me, for example the Dot Formula. The examples are based on real-life scenarios, and compare different approaches, explaining why one is better than the other. The examples are also very well illustrated with tables showing how the Buffer Content looks after one or more keystrokes.
Mode of use
Cover-to-cover read, or as reference guide, both approaches work. Practicing the examples in Vim while reading is recommended, it helped me memorizing the keystrokes better. Apart from that, as noted here, changing 100% to Vim for all my projects and text editing has been a great help to get better.
I learned a lot
I added quite some things to my standard repertoire: diw, df
Two more things I liked about this book: 1. Practical Vim shows you how to get by with Vim’s core functionality (almost no plugins), 2. a lot of links to Vim's Built-in Documentation and external resources.
I think this book and the author's screencasts are both unmissable to become proficient in Vim.