After reading, I think, every ruby on rails book that currently exists, I think that this one is definitively the best one. This book succeeds in that it takes the "magic behind the scenes rules" that exist in ruby on rails and actually ... tells you what the rules are!
This is as opposed to most rails books that basically give you a list of API functions. In stable programming languages, this latter approach is fine, but not in rails, which changes so fast that virtually the moment a book is released, a portion of the code inside of it no longer works.
I was initially a bit skeptical about the Head First approach, due to the amount of space taken up with pictures, diagrams, imaginary dialogues between personified concepts and that sort of thing. However, I've found the book both educational and amusing. While it's not getting me through anywhere near as much material as other books like the iconic "camel book" of Perl, I find that I can remember and use what I have learned.
Great book. The Head First series really has this teaching thing figured out.
This book teaches far more than just Rails - I highly recommend this book to anyone seeking knowledge about the View Model Controller architecture, Ajax principles, and REST. I wouldn't have been upset if they explained more about Ruby though.
Good introduction to Rails. As usual the Head First way is quite different from your average technical book which makes it quite a pleasant read. Didn't go as much in depth as I hoped it would.
This book helped improve my Rails vocabulary and taught me some important things I had missed when learning the basics. It is very out of date but still worth the read.