CAMERA:

WASD - Move

Space/Left Shift - Move Up / Down

Left Click - Orbit

Right Click - Pan

F - Center on current selection

TRANSFORM:

Drag axes to translate objects

Hold CTRL for more fine-grained translation

Del - Delete

C - Duplicate

Z/X - Undo/Redo

IMPORT/EXPORT:

Use the buttons on the top right to Import/Export