Where to start on Rails4 : Links, Resources, Tutorials, Tips, References

Tutorials:
http://net.tutsplus.com/tutorials/ruby/digging-into-rails-4/
http://edgeguides.rubyonrails.org/
http://ruby.railstutorial.org/ruby-on-rails-tutorial-book
https://blog.engineyard.com/2013/new-in-rails-4

Two most important links:
http://blog.wyeworks.com/2012/11/13/rails-4-compilation-links/
http://blog.remarkablelabs.com/2012/11/rails-4-countdown-to-2013


Videos:
http://railscasts.com/episodes/400-what-s-new-in-rails-4
http://railscasts.com/?tag_id=38&view=list

Upgrading to Rails4:
http://railscasts.com/episodes/415-upgrading-to-rails-4
http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html


Features:
Many features can be found on rails-3.1 features
Asset Pipeline : http://edgeguides.rubyonrails.org/asset_pipeline.html

Turbolinks : http://railscasts.com/episodes/390-turbolinks

Russian Doll Caching and Cache Digests : http://blog.remarkablelabs.com/2012/12/russian-doll-caching-cache-digests-rails-4-countdown-to-2013