Lectern can be crafted with 2 Wood Planks (any color) and Manuscript (used to be a book).
A Lectern can be used to combine Manuscripts and the Bestiary, to unlock new chapters. The Bestiary goes in the left slot, and Manuscripts go in the right slot. The chapter options are on the right, to get them, click on the chapter you would like to have.
If a villager changes its profession using a lectern, it will turn into a scribe.