We've just posted a new guide to the Operations Manager library - the Reporting Guide. This guide consolidates all reporting guidance (with the exception of report authoring) in one place.
This guide also includes reporting scenarios to help you create specific reports to meet your business needs. Right now there are two scenarios - Availability and SLA. We're working on additional scenarios - performance, disk usage, etc. If you have additional asks, please let us know and we'll get a scenario published for you.
For enviroments that have multiples RS, is there any way to change in the SCOM console the references for the reporting services server?