Single Sign On is a really useful tool to save users having multiple usernames and passwords and enables them to use their corporate login details for other services. Single Sign On is not available with the Small Business version of Office 365, but is available with Enterprise versions. Single Sign On has many benefits, including, policy control, access control, reduced support calls, security and support for strong authentication.

To use single sign on you must:

  • Have active directory deployed and running Windows Server 2003, 2008 or 2008 R2.
  • Install all required updates for Office 365 from Microsoft.
  • Use the Microsoft Online Services Module for Windows Powershell to establish a trust with Office 365.
  • Plan for and deploy AD FS 2.0 on Windows Server 2008 or 2008 R2.

The full article for preparing Office 365 and Single Sign On can be found here: http://onlinehelp.microsoft.com/en-us/Office365-enterprises/ff652540.aspx

Another more in depth article can be found here: http://onlinehelp.microsoft.com/en-us/office365-enterprises/ff652539.aspx