Well-Read

Read all 19 Books of Power (1.6 content) - the skill books and perk books, not the mountain of ordinary letters. Sources: the wandering Bookseller (visits twice a season - the town crier announces him), artifact spots and treasure chests, certain shops and quest rewards. The Bookseller stocks a rotating selection including the dear ones like the Book Of Stars, so bring money (some run 15,000-35,000g).

Each book only needs reading once, and duplicates re-grant their effect - nothing is missable, the checklist is just patience and gold. The Special Items & Powers menu shows which you've read.