If you are approaching Sametime 8.5.2 administration with a background in Domino, you might be somewhat overwhelmed with all the new concepts and skills required by WebSphere Application Server. You can use the following links to accelerate your WAS learning and gain the necessary skills you need going forward.
Overview of IBM WebSphere Application Server (WAS) concepts for IBM Lotus Sametime administrators:
WebSphere Application Server V7.0: Technical overview:
System Administrator skills ...