Please see the following two PDFs for how to use the soft keys and hard keys on your Polycom VVX411 or Polycom VVX311 phone as well as some helpful shortcut key presses.
Hard keys are keys on your phone that don't change (anything on the phone that isn't near the screen)
Soft Keys are keys near the screen that change depending on where you are in the menu and what you are doing on the call.
VVX Commands (key shortcuts)
Polycom Commands (hard/soft keys)