This bookshelf idea was given by Austydude so go and check him out

Step 1: The Base

Put a 2 long book shelf and leave two gaps then do the same thing again as shown

Step 2: Make the Shelf

Raise the book shelf 2 high

Step 3: Dig

Dig the gap between the book shelfs and replace it with oak planks

Step 4: The Side

Put oak planks on the ends of the book shelfs as shown

Step 5: Back

Put oak planks on the back of the book shelfs ( including the end) then do the same thing on the other side

Step 6: Fully Back

Where that gap is between the book shelf put a wall 2 long and 3 high

Step 7: Shelfs

Put trap doors in that gap

Step 8: Top

Put oak wood half slabs on top of the book shelf

Step 9: Done

Put this in a mansion I highly recommend it

Step 10: How to Get Your Idea on My Tutoral

Okay so this is how it works on my channel you post in a comment what you want me to build and your idea will be on the tutorial that you want me to do.like this one this was wanted to be done by Austydude.he makes minecraft stuff so go look at his channel