This is a perfect combo of my two favorite ideas for that space under the stairs leading to the basement. A reading nook AND book storage and shelves . assuming that there is enough space for this there.
Idea: Branch staircase and rough wood steps. The Adirondacks country house's main staircase railing is crafted from tree branches and logs. Notice the use of a variety of natural woods in the unfinished wood walls and the rough hewn wood block stairs.
I want to do this for my kids to make reading exciting - for every stair, we'll read the book. Staircase to Knowledge by sungazing: Stairway to the reading room at The Magic House, St. Louis Children's Museum in Kirkwood, MO