Steps to creating a new Rails app - from https://github.com/roa-2015/shopping_cart_example

new_rails_app

$ rails new "app_name" --database=postgresql --skip-test-unit

$cd "app_name"

$ git init

$ git add -A

$ git commit -m "first commit message"

install RSpec Rails - https://github.com/rspec/rspec-rails

Add rspec-rails to both the :development and :test groups in the Gemfile:

  group :development, :test do
    gem 'rspec-rails', '~> 3.0'
  end

run...  
$ bundle install
  
Initialise spec/ dir...   
$ rails generate rspec:install
 
use rspec to run commands... rspec or bundle exec rspec
  
Removing Turbolinks (Rails 4?)
  http://blog.steveklabnik.com/posts/2013-06-25-removing-turbolinks-from-rails-4
  http://blog.flightswithfriends.com/post/53943440505/how-to-disable-turbolinks-in-rails-4

$ rails generate resource Name name:string description:text price:integer 
(generate model etc  --  field:type)

$rake db:create

$rake db:migrate

Add some seed code to db/seeds.rb
$ rake db:seed

Use if want to check data
$ rails console

Testing - see other Gist

When creating/adding to a controller
Is named the same as your model if a resource controller but plural and with Controller at the end.
Inherits from ApplicationController
Add the first action like index
Create a folder in views with the same name as the controller.
Crate a file in the new views folder with the same name as the controller action.
Add a route to point to the new controller action in the config/routes.rb file.
If it is a resource you can uses resources to create RESTful routes.
Also add a root URL for the homepage if you haven't done so.

rails server / s
Run rails s to start up the server and visit the site.

Add CSS file to assets/stylesheets/ to add styles to site.

As you build up routes you can see them all with rake routes.

REMEMBER to run
  rake db:mirgrate
  rake db:seed
  - as required

And prepare you test db
rake db:test:prepare