Again, something that's been sitting in a folder in my mailbox for a while is this link to an article by Edwin Yuen, a Technical Product Manager based in the US, who covers System Center Virtual Machine Manager.  Published in January, it's still pretty fresh, and very relevant, as virtualisation becomes more and more mainstream, and management becomes more and more important.

Edwin goes through aspects such as the Admin Console, Intelligent Placement, V2V, P2V and more.  He even throws in a bit of PowerShell for good measure :-)

http://www.microsoft.com/technet/technetmag/issues/2008/01/SCVMM/default.aspx