I just received my Ruby on Railsbook a couple days ago. I've been waiting for a while now. Amazon originally said it wouldn't ship until the first week of September, so I'm kinda surprised. I got it a month early.
It's organized pretty well, and has just about all you need to know to build pretty complex Rails apps. But it's a small book (well, smaller than I would've imagined). Right now, I'm going through the earlier chapters just in case I've missed anything by learning solely by online tutorials. I've kinda peeked around the book and I'm pretty impressed.
Rails makes web application development really easy. So easy, in fact, that if I need to work with any amount of data, I hack together a database and a generate a scaffold to give me a head start. Then, with minimal modifications to models, views and controllers of certain classes, I have an application with a decent UI to allow me to create, modify and process the data. All in about 5 minutes. Purdy slick, huh?
I'll post more soon. I'm doing my entire website using Rails. My roommate knows some good design people, so it won't just work well, it'll look good, too.. ;-)