Rails is great - it saves you loads of time by doing lots of things for you. But sometimes that can feel like just too much magic and you want to get to grips with what’s actually going on.
I wrote a short email course about how views work in Rails, nothing too in-depth, but just enough to give you an understanding.
I hope you find it useful: http://theartandscienceofruby.com/2015/11/09/392-how-views-work-in-ruby-on-rails/