Here is my complete process before this last Step:

I have a Hosting named Hostmonster.

Using SSH conection the ruby on rails is running on my hosting.
My link shows

Welcome aboard
You’re riding Ruby on Rails!
Getting started
Here’s how to get rolling:

1.- Use script/generate to create your models and controllers
To see all available options, run it without parameters.

2.- Set up a default route and remove or rename this file
Routes are set up in config/routes.rb.

3.- Create your database
If your application was created with the Cpanel Rails utility then your application has been set up to use MySQL as it's database backend. Make sure that you create a database for it to use inside of your CPanel and then edit config/database.yml with your username and password. By default Rails uses SQLite. If you are using the default Rails configuration then you will need to run rake db:migrate to create your database.

I have 2 DB created, the Production DB and the Development DB

Everything looks fine at this step.

I have my aplication (I downloaded from internet only for example purpose, this runs on Ruby and rails of course)
These are the files in my App downloaded:

..
[]app
[]config
[]db
[]doc
[]lib
[]log
[]public
[]script
[]sysconfig
[]test
[]vendor
.gems
.hg_archival.txt
.hgignoreCapfileideax
.tmproj
LICENCE
Rakefile
README
tsearch2.sql

I have 2 folders created on my Hosting, the Hidden and the "public" folder

In my hidden folder I have the clean structure of rails I think.
..
[]app
[]config
[]db
[]doc
[]lib
[]log
[]public
[]script
[]test
[]tmp
[]vendor
config.ru
Rakefile
README

And in My public folder:
..
[]cgi-bin
[]images
[]javascripts
[]stylesheets
.httaccess
400.shtml
401.shtml
403.shtml
404.html
404.shtml
422.html
500.html
500.php
500.shtml
default.html
dispatch.cgi
dispatch.fcgi
dispatch.rb
favicon.ico
index.html
robots.txt

That's all what I have to say, I think the problem is creating the connection here "Routes are set up in config/routes.rb."

I think that's my problem, let me know if I'm OK.

You must know I'm "cero" in linux commands.