Cut - Command-X
Copy - Command-C
Paste - Command-V
Select All - Command-A
Undo - Command-Z
You can then press Shift-Command-Z to Redo, reversing the undo command
New Folder - Shift-Command-N
Open - Command-O
Open the selected item, or open a dialog to select a file to open
Save - Command-S
Find - Command-F
Find again - Command-G
Find the next occurrence of the item previously found. To find the previous occurrence, press Shift-Command-G
New Tab - Command-T
Close window - Command-W
Hide the windows of the front app - Command-H
To view the front app but hide all other apps, press Option-Command-H
Minimize - Command-M
To minimize all windows of the front app, press Option-Command-M
Full Screen - Control-Command-F
Print - Command-P
Force quit - Option-Command-Esc