I've been scratching my head for a day or so trying to learn FIM.
I attempted to walk through this tutorial which is one of the things I want to use it for - but I couldn't get it to work (users don't show up in FIM).
I am following this other tutorial which uses a simple CSV to popular users in FIM - which I also can't get to work.
I think part of my problem is that I don't seem to have any users in FIM (this is from a fresh install): http://i.imgur.com/0ONOP.png
I have read from many sources that you should at least have administrator in there.
Also I get export errors from the CSV tutorial that say "The endpoint could not dispatch the request."
I figured out my problem - by default no users will show up in that page. You have to actually search if you want to see users.
Searching for % will display all users in FIM.