Recently, I've been interested in learning Ruby on Rails, but at the beginning of my quest I wasn't sure where to begin, there are a lot of documentation in the Web that I could use but I wanted some structured tutorial that guide me through my first experiences with Rails.
Fortunately, the company where I work bought the book Ruby on Rails Up and Running by Bruce A. Tate and Curt Hibbs, so I took it and started reading it and what I found was exactly what I was looking for, a beginners book.
With this book, you can learn the basics of Active Record and Active Record Relationships, Scaffolding, Views, Migrations, Ajax and a bit of Testing.
It is not too long, so you won't feel intimidated by it. It is a good place to start, trust me!
I recommend it!