The Essential origins ebooks is a few introductory monologues by Tiny Gork where he shares the general history of the Shadow Council. They are a great start if you wanna aquaint yourself with the core story of the Shadow Council.
Tiny Gork has written down his thoughts and knowledge of the Shadow Council in a few short volumes.
First issue: The essential Shadow Council origins part #1
in this issue Tiny Gork goes back to the beginning and talks about the creation of the council and how mistrust slowly creeped into it. He also explain briefly how they created their own worst enemy and how he planned to move against them.