The "Resources" page is a place for you to upload class and project related files that are NOT stored in Google Docs (Google Docs related to your projects should be linked directly on your Project posts, on the Project Page). You can create folders to hold groups of files - for example all files related to a single project can be grouped in a folder bearing that project name.
Create a folder by clicking the "Move to" button and selecting "New Folder".
Again: The "Resources" page cannot be used to upload a document created in Google Docs. It is only for documents that you already have on your computer and want to upload to your site.