Manning has provided a free chapter (Chapter 14) of Rails 3 in Action.  This book was written by Ruby community leader Yehuda Katz and Ryan A. Bigg.  This chapter shows you part of the process of deploying a Rails application to a new Ubuntu install—creating a user account.  It gives instructions for using Vagrant as well.  The chapter "Creating a User for the App" is in PDF form and it is attached below.