Microsoft did a good work with Windows Server 2012 and 2012R2 documentation. They put together all TechNet documentation to one PDF document, so now you can have concentrated all the server documentation in one single file. It is complete, easy to find (OK, there are approximately 8000 pages…) and all in one place. Very nice.
A voice from Microsoft confirmed that the Exam 70-323 is not obligatory any more. At the end of August, it will be added the exam 70-324, which is the “light version” of 70-323. It is especially developed for small businesses and it will not have complex questions about hybrid and big enterprise environments.
I suggest you, that if you are interested in doing this exam, to join Jump Start.