If you're the friend that everyone asks for reading recommendations from, you might be skilled in booklore, or knowledge gained from or related to reading.
The term booklore is sometimes used for what is also called book learning — knowledge gained from books, through formal education. But sometimes it can also refer to lore about books, rather than lore from books. This sense refers to information about the history of publishing, printing, and binding books. This type of booklore is great to know if you want to learn more about the historical side of literature, or the literature side of history.