Use CTRL for Windows and CMD for Mac OS X:
CMD / CTRL + S: Project Save
CMD / CTRL + Z: Undo
CMD / CTRL + Y: Redo
While hovering the mouse cursor over the timeline
CMD / CTRL (Hold down) + Mouse Scroll: Timeline Zoom
CMD / CTRL (Hold down) + Left Click: Multiple clip selection
Shift + Mouse Scroll: Horizontal Timeline Scroll
Ripple Split : SHIFT (Hold down) + Left Mouse Button drag: Cuts multiple clips on different tracks at once and moves them in the direction of the mouse drag creating a gap where other media can be added.
Ripple Move : Select the clip + SHIFT (Hold down) + Left Mouse button drag: Moves media files but keeps their relative position from each other
Click and Drag: Multi-select clips from your timeline
While hovering over the canvas
CMD / CTRL (Hold down) + Mouse Scroll: Canvas Zoom
SPACE (Hold down) + Left Mouse click and drag: Canvas Pan
Copy and Paste
CMD / CTRL + C: Copy elements in the timeline or canvas
CMD / CTRL + V: Paste elements in the timeline or canvas
CMD / CTRL + X: Cut elements in the timeline or canvas
Pasting an element will position it on a new track at the top of the timeline where the play-head is positioned.
Cut and Delete
S : Makes a cut at the position of the play-head
DEL: Deletes the selected clip
SHIFT + DEL: Ripple Delete (deletes the clip and everything on the track moves to the left)
Note: Some Mac OS X systems don’t recognize CMD combinations for shortcuts in the browser if that happens try to use Control instead.