Topic: Rails Cookbook
I just got the Rails Cookbook and have been skimming through it. From what I have seen, it looks like a good compliment to the AWDwR book. I recommend you read AWDwR while learning Rails, then after you get the hang of things, buy the Rails Cookbook. It is part reference and part tips & tricks. A few areas overlap, but I find the "problem/solution" recipe approach makes it easier to look something up than the wordy style of AWDwR.
The recipes are nicely grouped together based on the topic, but as with most cookbooks I'm finding the target audience and flow of the recipes to be inconsistent. The recipes range from beginner to advanced, generic to specific and they are all mixed together. But at least this way everyone will find something useful in it.
Although it makes a nice reference, it is far from complete. It is very hit-and-miss when looking up something specific. The Active Record, Action Controller, and Action View sections of the book feel like they hardly scratch the surface. But this isn't exactly a complaint as it was never intended to be a reference - just a collection of hundreds of useful Rails recipes - and for that it works extremely well.
The Debugging and Performance sections of the book are pure gold. That information is hard to find on the web and it is very useful to have it in one place.
If you have AWDwR and are desperate for another Rails book, get this book. I don't know if it has any information that isn't already online, but it's nice to have all these little nuggets in one place. It is filled with "Oh that's useful, I never knew that" moments. It reminds me of hundreds of useful Rails blog posts all wrapped together in a book.