Expose Guides

Exposé is an awesome feature of the Mac OS X user Interface that makes it easy to see, access, or hide application windows and documents.  It's a great feature to help you work with the clutter that tends to build up when you are using multiple applications and/or documents.
Expose can be configured via its preferences within Mac OS X System Preferences.  The location depends on the version of Mac OS X.  This guide will highlight how to make changes under Mac OS X Leopard (10.5) and Mac OS X Tiger (10.4).
You can switch to another Expose mode without having to exit the current mode.  The actions you take will depend on the Expose configuration.
If your keyboard has speaker adjustments on the F9, F10, and F11 keys the preconfigured keys in Systems Preferences won't work.  This is often the case for newer Macs and for Apple's aluminum-based keyboards.