I am going through and building vCenter in a sandbox. I am following Derek Seaman's excellent blog to assist me. His blog was written in September '12 and at that time he recomended vCenter 5.1.0b. I have checked the evaluation download and the current version is VMware vCenter Server 5.1.0 Update 1 and modules. Then I have found operations management suite 5.7 that supports VMware vCenter Server 5.1 only (what about 5.1.0b, etc.). I am getting confused on the versions and have done several searches trying to find a document that explains all of this. Any pointers to URL, documents, etc. that you experience vCenter users can point me to or provide assistance with this? It is fun trying to learn it all just frustrating when I cannot find it on my own. 
Thanks,
Vis