With all the “how to build an application in Rails” books that have come out this year, do we need more? Yes!

RailsSpace: Building a Social Networking Website with Ruby on Rails (Addison-Wesley Professional Ruby Series)

RailsSpace is a well-written, insightful introduction to Rails that uses the creation of a simple social networking application to tell the story. It’s not a reference book, and it may move too quickly for absolute beginners. But for more experienced readers who are new to Rails, or for Rails developers with some experience who are looking to learn a few new tricks and pick up some best practices, this is a great book. The step-by-step creation of the social network application (and thankfully not another shopping cart) provides a cohesive structure and creates natural opportunities to introduce a wide variety of topics.

Author Michael Hartl was previously a physics instructor at Caltech, and his teaching experience shows. The book progresses naturally, explaining just enough as it goes along to keep the reader oriented without too many diversions. This is a real challenge in an introductory Rails book, since there’s a lot of pieces you need to understand to some degree before it all makes sense. Coauthor Aurelius Prochazka is a very experienced web developer, and this too shows through. The book is full of insights and best practices that make it more than just an introductory text, and also make it an enjoyable read.

Although the book only scratches the surface of many advanced Rails topics and doesn’t go too far into Rest or Ajax, it covers well a number of topics that are often neglected in introductory books. Testing is addressed nicely; the book doesn’t use a test-driven development (TDD) approach, which interferes with learning the basics of Rails, but it does show how to test each feature after it is built. It also has a good section on searching, covering both the use of Ferret and the creation of searches using multiple, specific model fields.

There’s a companion web site, built using the code from the book, at which you can browse the source code. You can also download a sample chapter, RESTful Blogs.

Experienced Rails developers may want to wait for two very promising books due out later this year: Mike Clark and Chad Fowler’s Advanced Rails Recipes, and Obie Fernandez’s The Rails Way.