A Clash of Kings - A Mount and Blade: Warband Modification Wiki

Books can be very useful in the Mount&Blade series. Their primary purpose is to give free boosts to your skills or attributes without having to level up. You can purchase them from Book Merchants, found in taverns. Reference books provide the bonus by simply being in your inventory. You do not have to read them, but losing the book will result in losing the bonus and the effect does not stack if you have more books of the same kind. Reference books can also be stored in companion inventories to provide a bonus to their skills

Other books must be read, but the bonus is permanent. In order to read a book, you must go to the camp menu and "select a book to read". You will then read this book whenever you are resting, such as when you have set up camp, or are staying in a tavern. Once the book is finished, you will get a boost to a certain skill or attribute. These types of books require approximately 143 hours to read.

They can only be read once, and companions can also read books, provided they have the required intelligence.

It might be advisable to read books during the night rather than the day, because of the movement speed penalties.

Bonuses can't pass the 10 level limit of skills, so make sure you only level up to 9 the skills of books you intend to read or keep as reference.

Book Merchant

Book Merchants are educated men peddling books for those who wish to better themselves. You can find them in taverns. Books are expensive, but often well worth the benefit.

Book Merchant inventory varies somewhat between taverns, however their space is partially shared as items sold to one book merchant can often be found in another's inventory.

(from The Ultimate Warband Guide)

Name Weight Description Requirements
Essay on Logic by Grand Maester Gerardys 2.0 +1 to intelligence (ar) 10 intelligence
The Seven Pointed Star 2.0 +1 to charisma (ar) 10 intelligence
A Compendium on the Blackfyre Rebellions 2.0 +1 to tactics after reading 10 Intelligence
The Conquest of Dorne 2.0 +1 to persuasion (ar) 10 Intelligence
Life of Aegon the Conqueror 2.0 +1 to leadership (ar) 10 Intelligence
A History of the Iron Bank of Braavos 2.0 +1 to trade (ar) 10 intelligence
On the Art of Fighting with Swords 2.0 +1 to weapon mastery (ar) 10 intelligence
The War of Volantene Aggression 2.0 +1 to engineering (ar) 10 intelligence
The Great Book of Magic 2.0 1 to looting (ar) 10 intelligence
List of Books (2.2)
The Diary of Gralmaq mo Eraz 2.0 +1 to prisoner management (ar) 10 intelligence
Wonders Made by Man 2.0 +1 to spotting (ar) 10 intelligence
A Short Treatise on the Great Spring Sickness 2.0 +1 to first aid (ar) 10 intelligence
Map of the Known World 2.0 +1 to path-finding (ar) 10 intelligence
The Book of Healing 2.0 +1 to wound treatment In Inventory
On the Unsullied 2.0 +1 to trainer In Inventory
On the Citadel and Surgery 2.0 +1 to surgery In Inventory
Merchant's Ledger 2.0 Tracks Assessed Prices
Book of Patrons 1.0