Books of Knowledge are Wealth that you can find in any region of Norway or England in Assassin's Creed Valhalla. They are the various skills that Eivor can have for combat. There are two categories: melee attacks and ranged attacks.
The skills can be an aid in concealing your character for assassinations or even a fairly insightful way to deal heavy damage. You will be able to equip 4 skills of each category - melee or distant - so you will have to make a choice. Moreover, it's possible to increase the level of your aptitude by learning a similar knowledge book. Let's go for Cent's books.
Abilites in Cent
Location #1
Location #2
Original content by Camille"Effylia" Bouin.