Suggestions wanted

I know there are lots of creative souls out there and I need your help. I really want to reorganize this space in the play room to make it more functional for my girls and easier for me to keep organized from day to day. The girls love books! They love them so much that we are completely out of space for them. The easy answer would be to just buy another book shelf but I really don't like that idea. It's so hard to find their favorite books like this. We have a tub on the table for Kinsey's decodable readers, the Tag reading materials, and Kaitlyn's letter cards...but I really don't like that either. If you have any ideas I would love to hear them, see them, or send me a link to something you've found.