Complete newbie stuck at the first hurdle

I am new to Pluto and new to Maven ... double trouble!

The installation instructions start with:

   "Building Pluto with Maven 2
   If this is your first time building Pluto with Maven 2, edit ~/.m2/settings.xml and
   add the <pluginGroups> element:
   . . .
   . . ."

I am running on OS X and Maven 2.0.6 is already installed on OS X. However; I do not have a 'settings.xml' file to edit. Uh oh!