The easiest method for submitting content to Digital Commons @ Wintrop is to email it directly to firstname.lastname@example.org. Librarians at Dacus Library will upload the content for you and save you time.
I don't have electronic versions of old working papers that I'd like to include in the repository. Is it okay to scan the printed page to a PDF file?
It depends on what the journal allows, which is usually specified in their agreement with the author. If it would not violate copyright to post the reprint on your repository site, you're welcome to do so. Permissions for many publishers can be found at SHERPA RoMEO.