The key tip Microsoft showed you, in case you missed it, is simple: Move your mouse to the corners of the screen. As with all things Microsoft, though, it's not as simple as you might think. In different contexts, moving your mouse to a corner means different things.

When you're in the Start screen, moving your mouse cursor to the upper right or lower right brings up the Charms bar.

The Charms bar is simply a set of five icons on the right side that represent key system functions, and the bar is available wherever you are in Windows--even when you're in the traditional desktop. At first, you'll primarily care about two of the icons you see: the center, windowlike one, which returns you to the Start screen; and the Settings icon, which is the bottom one. The Settings icon is key, because that's where the shutdown/restart button now lives.

Now, move your mouse to the lower left corner, and you get...nothing. Nothing, that is, until you run something else--your first Windows 8 app. Indeed, if you have active apps running, moving your cursor to the lower left will show you a small thumbnail view of the most recent app running (including the Windows desktop.) However, mousing to the lower left is how you primarily return to the desktop. It's just how you get back to your most recently used app.

Now, move your mouse cursor to the upper left corner, let it hover there for a moment, and then move the cursor down slightly, and the app-switching bar will pop up on the left side of the screen. This bar displays a thumbnail list of all currently running apps. You can then drag an app thumbnail to the right to make it take over your screen. If it's a Windows 8 app (and not a desktop program), you can run it in split-screen mode by dragging it down, and letting it dock to the left or right side.