Save two seconds by skipping the Empty Trash dialog box. Be sure you really want to empty it because they're not going to ask if you're sure.
It's easy to type an accent mark on a Mac. As usual, the good stuff starts with the Option key. Takes a second to learn how.
Resize Finder windows and graphic objects from the center by holding the Option key while you drag an edge or corner. Grow the item while keeping the item's center fixed.
Changing sound options doesn't require a trip to the System Preferences. Do it all from the Sound menu, with an Option-click.
Here's what those mysterious symbols mean in the Mac's menus. When I first got a Mac I didn't know. Maybe you still don't. But now you do.
Apple took away the Save As... menu item. That's too bad, because it's very handy. Actually it's still there, if you know how to bring it to the surface.
Command-W does what a click on the red button does. Command-Option-W does what an Option-click on the red button does-- close all windows for that app.
Apple hides your Library folder because they don't want you accidentally messing it up. When you have to get into it, use the Option key and the Go menu.