The repo cloning needs to be done this way:
  *  Launch the server instance using either <tt>fossil ui</tt> or <tt>fossil server</tt> using the first repo.
  *  On the user's own PC (where the clone will be kept), run <tt>fossil clone or IP address&gt;:&lt;port #&gt; clone_repo.fossil</tt> to process the cloning.

The documentation's a little sparse than what I would have liked, yes, but I've found the text within the "help" command sufficient for what I needed. Most of the wikis go deeper into some of the concepts involved with Fossil and DVCS in general. Is there anything in particular that you're looking for?