gistfile1.txt

<h1>New product</h1>

Are you creating a new Product object in this action?  Try this:

<%= @product.inspect %>

If nothing shows up, then you need a <pre>Product.new</pre> in this controller action.

<% form_for(@product) do |f| %>
  <%= f.error_messages %>

  <p>
    <%= f.submit 'Create' %>
  </p>
<% end %>

<%= link_to 'Back', products_path %>