Exchange server 2012 configuration
We're asked for a guide to configure Exchange 2012 quite often but there isn't actually a 2012 version of Exchange. What most people mean in these cases is "the Exchange that runs on Windows 2012" and that in turn could be either Exchange 2010 or 2013.
So these here are the two possible guides for "Exchange 2012":
Configuration of Exchange 2010 Server (also for Windows 2011 SBS)