If you are learning about Microsoft OMS you now have a new resource that you should definitely check out: “Inside the Operations Management Suite” by Stanislav Zhelyazkov, Tao Yang, Pete Zerger and Anders Bengtsson. I have been working with OMS for quite a while now and I still found a lot of great information in here that I was unaware of. There are even some features which are discussed that you won’t see anywhere else including Alerting, Power BI integration and near real-time performance counters. There are several PowerShell examples in the book (available for download) and they even include a full chapter dedicated to management pack authoring in OMS. The book is organized logically and flows well through the various topics.
I’m impressed to see a free e-book with 449 pages on a topic like OMS. It is available for download at: https://gallery.technet.microsoft.com/Inside-the-Operations-2928e342