Alright, so I’ll readily admit this has nothing to do with UI Design. Nevertheless, if you’re trying to slog your way through the Ruby on Rails API documentation or official wiki you may be much better served checking on Ryan Raaum’s excellent primer on Rails first.
Raaum’s Rails Reader has several advantages over the other two resources mentioned: one, it’s much easier to find your way around than in the API docs. Two, it actually recommends best practices (check out the ActiveRecord content, for instance, which I find invaluable). Three, it tends to not be self-contradictory, which is always useful when you’re just getting up to speed on a new technology.