With Google Apps, you can have your own private network without buying server hardware, knowing how to set up servers, or worrying about maintenance. Google provides all of the expensive infrastructure, IT management, mail servers, chat system, administrative tools, etc., to create an extranet at no cost to you. Well, almost no cost; it does require that you have your own domain name for your web site.
This Short Cut explains how to acquire, configure and administer your own domain using Google Apps. It discusses configuration options that are both domain- wide and user specific. It also covers what you'll need to do to migrate an existing domain to Google Apps.