You can use the Dock to switch apps, but your Mac also has an app switcher. To perform this maneuver on a Mac, press Function-Delete. The delete key on a Windows keyboard does the opposite and deletes the character to the right of the cursor.

That is, it deletes the character to the left of the cursor. The delete key on a Mac, however, acts like the backspace key on a Windows keyboard. On a Mac keyboard, you get only a delete key. Windows keyboards have a backspace key and a delete key. The missing backspace key on a Mac keyboard is another difference that might trip up Windows converts. To quit the app, use the keyboard shortcut Command-Q. Unlike with Windows, the X button on a Mac closes the window but does not quit the app. If you are coming to Mac after a long tenure with Windows, then you might get tripped up when you click the red X in the upper-left corner of a window only to discover that the app is still running after the window closes. Here are ten shortcuts for general Mac use that didn't fit in any of the above apps.

I've covered shortcuts for Finder, iTunes, Safari and Spotlight.