Here are the links to Infrastructure As A Service guides published by Microsoft. The deployment guide would be quiet useful if you are planning to build out a System Center lab, I am sure some of this could be leveraged for a System Center 2012 R2 test lab.
Infrastructure-as-a-Service Technical Guidance for Hosting Service Providers
Infrastructure-as-a-Service Product Line Architecture Fabric Management Architecture Guide
Infrastructure-as-a-Service Product Line Architecture Fabric Architecture Guide
Infrastructure-as-a-Service Product Line Architecture Deployment Guide