I am currently studying toward gaining the MCITP Virtualization Administrator certification of which the 70-699 is a required exam. Below are a couple of links that will give you some good preparation material for studying toward the certification:
Administration Video Series:
Free eBook: Understanding Microsoft Virtualization Solutions (Second Edition) in PDF format:
Hands on testing is always the best way of learning but this will at least give you a good start point if you are new to the technology. Also worth remembering that virtualisation is a big part of cloud solutions.