Ruby Best Practices book starting its open source release early.
blog.rubybestpractices.com
blog.rubybestpractices.com
I think the rails community, in general, is rather unapproachable from the outside. Something that simplifies the process of getting up to speed quickly will be greatly appreciated.
A quick example: where do you find anything about named_scope on guides.rubyonrails.com?
What my book won't tell you is anything about Rails's API.
I might not have phrased it that way. The community is very open about helping new developers.
However.
The documentation covers the mechanics of using Rails but you have to know what you're looking for to find anything. Most of the best information is in blog posts or presentations, has a shelf life of 6 to 8 months, and the only semi-reliable way to access it is Google.