Valid for [Beta 0.9] Rel 6 Rev E (deadly donkey)
Keystrokes
Del key Delete selected objects
+ (numpad) Zoom In
- (numpad) Zoom Out
Arrow keys Pans the view in the direction of the arrow (assumes numlock off on numpad)
CNTL-A Select All Objects
CNTL-Left Continued left clicks with CNTL key selects multiple objects
CNTL-C Copy object to clipboard
CNTL-V Paste object from clipbaord
CNTL-X Remove object and copy to clipboard
CNTL-Z Undo last operation, if any
CNTL-Y Redo last undone operation, if any
CNTL-U Union selected objects
CNTL-J Join selected objects to a given tolerance where possible
CNTL-P Convert selected object(s) to Polylines
CNTL-R Convert to Region
CNTL-G Toggle "Snap" to "Grid" mode
CNTL-T Generate Toolpaths
CNTL-O Open file
CNTL-S Save file
CNTL-SHIFT-A Select all objects on current layer

Mouse Input
Left Button Select object if on object, clicking on empty space deselects all objects
Left Button Drag Dragging the Left button to form a rectangle around objects will select all objects completely enclosed by the rectangle.
Right Button Drawing window menu
Middle Button Drag Dragging this button will change viewpoint (Translate)
Mouse Wheel Zoom in 3D view (same as + and - on numeric keypad)
ALT-Left Button Dragging will rotate object in 3D view (may be changed in Tools->Options)
ALT-DoubleClick Reset the view, same as View->Zoom to Fit