Has anyone used iCloud to share Pages documents between Ipads?

Hi All,

I'm trying to use iCloud to share pages and numbers documents between a group of iPads. Each iPad belongs to a different person who has their own personal documents on their respective device. Is it possible to set this up in a way so that only the documents you select to share are put into the cloud, or does every document that you create get uploaded and shared automatically?

Thanks,

-Owen