I have around 25 websites created, some of the URL's have been created to direct to certain parts of my websites.
I've set up a test website, using a subdomain I created (emd) to the fastmail domain, but of course you can set that to your own domain:
http://emd.fastmail.com/test/
This lists the files in the test folder, but if you want a direct link just open the file in question then copy the URL from your browser, for example:
Open testfile.pdf, the URL is shown as:
http://emd.fastmail.com.user.fm/test/testfile.pdf
You can copy that as a direct link.