Is there a users manual available for the DNN-Download module?

Also, after playing with it for a bit I it appears to me that it does not work with other modules.  For example it does not interact with the links module or document module.  So to prevent any user that does not have the correct permissions from typing in the URL to a file, thus by passing DNN security (bad flaw), you must load the file into the DNN-Download module, which then adds an extension and copies it to a different directory.  Is that correct?