Minecraft wiki entry for Development_versions, associated text: Can now be crafted from slabs and bookshelves.
Right-click empty lectern to place book.
Right-click lectern with book to open.
Multiple people can read the book without having the item.
Current page is persistent and shared between all readers.
Book can be removed from it.
Emits redstone pulses when page is changed.
Redstone comparators can be used to get book reading progress.