What should I upload in this Develop Solutions step?
Consider uploading images (JPG, GIF) of your rough digital model. It's ok if your model is still a work in progress. Show an axonometric or perspective view with people, which will help others understand the scale of your library.
How do I develop solutions?
Look at all of the ideas you gathered in the last step. How do those respond to the needs of the space? Learn more about developing solutions here.