Use the File Upload content type (as the pdf above). This is great for listing files under 5mb such as pdfs or word docs.
Slightly larger documents (under 9mb) can be uploaded to the Media Library and linked to within your page.
External hosting services such as Google Docs or Dropbox are better for sharing larger files (over 9mb).
The assumption is always that you are making documents available for public use. If you require restrictions on the publication of documents, please contact it.servicedesk@ncl.ac.uk for advice.