I’m Using Joomla For Site Building, I Just Wonder, How To Allow Users To “upload File” On My Site?
January 23, 2010 under FAQ
Without extensions, you can make one of your pages into an article submission page. From there, users can upload files and link to them just like you can from the back end.
You can also look at DocMan, or Remository in the Joomla extensions site.
http://extensions.joomla.org/extensions/popular
