Without DMS you only have the option of GOS Generic object services to link attachments to your objects. And with the right setup of a content repository this content can be stored somewhere outside the SAP database, just the link resides in SAP.
Use the SCN search on top right of the forum, search with: content repository GOS
then filter the search on the left to wiki and documents. There is good stuff that can help you.
Same is valid for the second part of your question, just search with: sharepoint content repository