Content Library Creation

We are the corporate Marketing team for a company that has many franchise owners. We have a lot of content we would like the franchise owners to be able to access, so need to create an organized and easy to use content library for them. Our initial thought is that this will be an excel document, but we're open to other suggestions. The content currently lives on our website and various platforms. We would provide the categories and would then need this person to organize and create the actual content library document.