Below are a few links I’ve used relating to MFA (in Azure):

1. Securing access to cloud services with Windows Azure MFA
   • http://technet.microsoft.com/en-us/library/7a9c56cf-72f1-4797-8e86-a9a2d9569ef6#emailtemplate
2. Windows Azure MFA for Office 365
   • http://technet.microsoft.com/en-us/library/dn383636.aspx