In order to help/assist administrators, Microsoft has published CHM file (complied help file) for Exchange 2013

http://www.microsoft.com/en-us/download/details.aspx?id=35395

2 files are available: one for hybrid deployment (don’t forget you need an Office 365 “2013 version” tenant for hybrid deployment) and one for On Premise deployment (don’t forget, if you have Exchange already deployed you need Exchange 2010 SP3 [planned] and Exchange 2007 SP4 [also planned])

 

In the same time, you can also download RTM Unified Messaging files

http://www.microsoft.com/en-us/download/details.aspx?id=35368