Upgrade (Prequisities)

Hi everyone i want to do transition of exchange server 2007SP3 to exchange server 2013.

I have tested it on windows server 2012 but now i got to install on windows server 2008 R2.

Experts please do guide me 
1. what are the Prequisities to install exchange server 2013 on Windows Server 2008 R2.
my mailbox and CAS will be on the same server.

I want to do the transition to Exchange 2013 CU2 and once i am done i would decommsion Exchange 2007
After that can i upgrade Exchange 2013 Cu2 to Exchange 2013 SP1?
Any prerequisites before the upgrade to SP1.