The File Manager is used to upload and organize documents, within SOLE, that you want to link to content in your course/site. For example, you must first load your syllabus to the File Manager before it can be linked using the Course Information tool. You can upload course lectures, syllabi, schedules, and lecture slides, etc and then link them to your course for students to access.
Remember, users in the course do not have access to the File Manager. They will not be able to view your files until they have been linked to content objects created within Course Content.