From: http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html
To create a new person you typically set up a new instance of Person in the PeopleController#new action, @person, and in the view template pass that object to form_for:
<%= form_for @person do |f| %>
<%= f.label :first_name %>:
<%= f.text_field :first_name %><br />
<%= f.label :last_name %>:
<%= f.text_field :last_name %><br />