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.
Second issue: The essential Shadow Council origins part #2
in this issue Tiny Gork continues his story about the councils nemesis and his plans for their doom. The Council tries to take pre-emptive actions, exploiting a possible weakness while the nemesis moves closer and closer to his end goal.