I'll second this. Is an excellent book. After each chapter I recommend to take your own distilled notes. After reading the book you will get a very solid base command knowledge in Vim. What I really liked about it is that you can read it without being distracted: go immediately to the computer to test things out, this is because he painstakingly took the effort to show in pages what actually happens after each time you press a keystroke. I truly appreciated this, because you can read the book anywhere and focus on Vim mechanics without the need to try everything out on the fly.