where to add action when getting started with rails

Hey there. I'm a complete noob when it comes to Rails, and Ruby for
that matter. I've been trying to make my way through the Getting
Started with Rails page on the RoR Guides site
(http://guides.rubyonrails.org/getting_started.html).

In section 5.7 of that page it says the following:

If you submit the form again now, Rails will complain about not finding
the show action. That's not very useful though, so let's add the show
action before proceeding.

post GET /posts/:id(.:format) posts#show

The problem I'm having is I don't know where to put this line of code.
Does it go in /config/routes.rb? If so, where?

Thanks in advance.

Rails guides are merely guides to using various features of rails, and not a guide to learning rails from a beginner’s POV. For that, I highly recommend http://ruby.railstutorial.org/ruby-on-rails-tutorial-book, which is a free online book.

Thanks very much. That's definitely helpful.

You can see this line when run ‘rake routes’. This line means that your app should have controller post with action show and also view show.html.erb in app/views/posts/. Also you should add ‘resources :posts’ line in your routes.rb. Then your became able to process HTTP GET request at /posts/:id

It was the good suggestion to learn online book, as you will understand how all components works.

Thanks Anton! I did see it when I ran 'rake routes' so that is good. I
appreciate the help!