Duck's Guidebook is a item-started storyline quest. It is started when you find and activate a "Green Notebook" (level 12 required). The notebook is almost always found as a drop from the Chaotic Orc Scouts in the zone, but bugged and rare drops have been reported on occasion.
The first objective is to kill 5 Chaotic Orc Scouts. Then you must find someone who knows something about the book. In this case, it's Traveling Merchant Lander, just south of Parpamu.
The second part of the quest causes the name to switch from "Green Notebook" to "Duck's Guidebook". It begins with Traveling Merchant Lander, and requires you to take the book to the owner, Traveler Duck in Willshire. Upon speaking with him, the quest will be complete.