Within the COOLSite Admin click the "Upload Files" section in the left menu under "My Website". This will bring up a page which will display all previously uploaded files and a section to upload new ones. The multi file uploader will let you drag -n- drop files into it for uploading.  There is also a Files and Folder button. Once the file has successfully uploaded it will automatically create a URL at the top of the page. Now you must copy the URL given to you on this page and use this URL when adding the file to your website using the editor. 

The Upload Files section allows the following files types to be uploaded:
(*.jpg;*.jpeg;*.jpe;*.gif;*.bmp;*.png;*.swf;*.doc;*.rtf;*.odt;*.zip;*.rar;*.wmv;*.wma;*.wav;*.mid;*.midi;*.mp3;*.mp4;*.txt;*.csv;*.xml;*.pdf;*.js;*.xls;*.ppt;*html;*.htm;*.mov;*.flv;*.ico")