Lecterns are a fun mechanic that allows players to display written books in a unique format. Instead of players having to pass the book to each other and opening it by hand, a book can be placed in a lectern and read by anyone at anytime.
A Lectern can be made by attaching a sign with the text "[Lectern]", to an enchantment table as shown. For a book to actually be displayed though, a chest with a book must be place adjacent to the Lectern. You can also place an item frame with the book inside it on the side of the lectern to have it display as well.
Multiple books can be placed inside a lecturn usign either method. If this is done, a new menu (pictured below) will appear to allow players to select which book they wish to read. If there is only one book, however, it will immediately display.