Keys	Action
LMB	Select
RMB	Context Menu
A, Alt + A	Select All, Deselect All
X / Delete	Delete Selected
Shift + A	Add New Object / Node
G, R, S	Grab, Rotate, Scale
Tab	Toggle Edit Mode
X / Y / Z	(While transforming) Constrain to Axis
Shift + (X / Y / Z)	(While transforming) Constrain to perpendicular plane.
Z	Change viewport shading (rendered / workbench)