You need three things: paper, leather, and a pinch of madness. Paper comes from sugarcane. Grow it near water, and it shoots up like a green rocket.
Leather is trickier. You have to murder a cow. Or a horse. Or a llama. Don’t think about it too hard.
Kill two cows, and you’re golden. One leather makes one book. Three papers make a book. The math is simple, the loot is real.