How to use the mouse buttons for

static viewing mode

• the left mouse key has 2 functions.

  A single klick changes the selection state of objects.
  Just click the left key while the pointer is located above an
  object. The state of the objects toggles between selected
  and not selected. Selected objects are displayed in white
  (highlighted).
  

  Klick the left mouse button and hold it down
  while pulling the mouse over the graphic window.
  A rubber-box will be displayed and after release the
  mouse buttton all entities will be selected.

• The middle mouse button changes the current view (tranlation, zooming) .
  

• The right mouse button acknowledges the selection of objects.
  Most processes prompt the user to select certain objects (left button), each of which has to be acknowledged by pressing the right mouse button.
  The right button offers the online help if it is pressed when the mouse focus is on a function button.
  

dynamic viewing mode

You can find more information at this site.

setting a new rotation and zoom point

You can find more information at this site.

Maus:

schnuckliges Wesen, auch: Kosename für Wesen auf höherer moralischer Stufe.

Die Maus ist ein gar nützlich Tier,
drum nützen auch wir sie hier.