i don't know on what the filemanager is based but you could look at /media/ for mounted devices.
you can open x-term and type "mount". this should output a list of all mounted devices and their mountpoints.

if it's nautilus-like the share won't show up anywhere in your filesystem automatically.

just take a look at this page:
http://ubuntuforums.org/showthread.php?t=297759