The Assassin's Creed seems to be a guide for Rogues. It's only mentioned in the World of Warcraft Trading Card Game.

Content

Chapter 1

"Leave nothing to chance." - about Premeditation

Chapter 2

"Every being has vulnerable spots; make it your business to know them all." - about Gouge

"With one well-timed strike, any opponent can be stripped of his defenses." - about Dismantle

Chapter 3

"Guts were meant to be gutted." - about Eviscerate

Chapter 4

"Let there never be rest for the weary." - about Coup de Grace

"Leave nothing the family can identify." - about Mutilate

Chapter 5

"Revel in the cool shelter of the shadows." - about Cloak of Shadows

Chapter 6

"Poison the body, and you'll numb the mind." - about Anesthetic Poison

Chapter 7

Chapter 8

"You need not always be hidden to get the upper hand in a fight." - about Surprise Attacks