2013
Microsoft recommends exposing Exchange directly to the Internet.http://blogs.technet.com/b/exchange/archive/2013/07/17/life-in-a-post-tmg-world-is-it-as-scary-as-you-think.aspx
Configuring Direct Access in a lab environment.
http://blogs.msdn.com/b/canberrapfe/archive/2012/07/12/simple-direct-access-setup-with-windows-server-2012-rp.aspx
Find out what features are in and what are out in Office 365 for each plan (e.g. E1, E3, etc)
http://technet.microsoft.com/en-us/library/office-365-service-descriptions.aspx
