Recently in Managing your files (Assets) Category
The following pdf file will provide screen shots, showing you how to insert images into your entries. The process is identical for uploading files.
Yes you can. You need to get the HTML code for the file. To get this information you need to go to the entry where you last used that file. In the entry area highlight the "Download File" and copy it. Create your new entry and in the body paste the download file information. This will create a link to the desired file.