Wood Book Shelves can hold up to 3 stacks of items, but will not display them.
Shelves of any kind cannot be found anywhere in the world nor with creatures currently, but can only be crafted in your crafting menu (default key "Q") - or at Crafting Tables that still exist in older worlds.
You can craft 1 Wood Book Shelf (as of R29 in February 2016) with:
- 1x Melted Wax made of Beeswax in a Forge or looted from Wood Treasure Chests or Stone Treasure Chests
- 6 Wood Slabs made of any kind of Wood or Logs in a Processor
- 1 Stone Rod made of Stone, Limestone or Bedrock in a Processor or found in Stone Treasure Chests
To use the shelves, place them into the world and interact with them (right-click or default key "f"). A small window with 3 slots will be displayed any you can put all kinds of stuff into these slots from your inventory by dragging & dropping with your left mouse-button. You cannot pick up the shelf again as long as items are still stored in it! If the shelf is empty, you won't need any Power Cells equipped to take it up though.
Wood Book Shelves are flammable! Be careful when placing Wood Book Shelves into hot environments like Savannahs and letting them touch fire or fiery blocks (like Hardened Lava), as that could ignite them. Liquid Lava and Fire Bombs will immediately set them on fire. If Wood Book Shelves start burning, also other flammable blocks (or items) nearby can catch fire, and this way even a whole forest or wooden house can burn down in the worst case.