You want want to start with the History of the world here, History of Endelwyne.
Following that, start your adventure with the group Endelwyne Campaign – First Adventure.
The rest of the Adventures are Listed Here: Endelwyne Campaign – Adventure List
You'll also want to familiarize yourself with some of the major themes in the Campaign. First The Wild Hunt and his Horde set the current state of the world in motion when they destroyed the Assarisan Empire and the Totems they had collected for centuries. For a list of all the Totem-Gods go here: List of Totem-Gods For a list of all the locations used in the game look here: List of Campaign Locations There are several tags you can use as well. Location, Player and NPC-Major and NPC-Minor are good places to start.