What is the best start point

Start point to read rails code?

http://github.com/rails/rails/tree/master

lol, thx:)

You could learn by focussing on one component only at a time. I wrote a guide on respond_to that guides you through the code Rails 2.3 uses: http://frozenplague.net/2009/04/how-rails-works-2-mime-types-respond_to/

Also, this should've really been on rubyonrails-talk...

wow, nice tutorials:)