Becoming familiar with all the guidelines for Windows 8 users is an essential part of being a Windows 8 developer. If you violate certain conventions, your application cannot even be deployed via the Window Store.
Learning these guidelines and conventions will take you a while. You can find a launch page for the complete set of guidelines at http://bit.ly/Win8UXGuidelines. You should study those carefully.
To set the stage, though, here are a few of the most important concepts, particularly ones that are probably at significant variance from the applications you have written before.
The earlier discussion of charms, app bar, and nav bar are part of the standard way apps are supposed to interact with the OS. So are contracts for Search and Share.
There are a number of other conventions in this general area of OS interaction. For example, your application should not have a Close button, or any equivalent functionality. A standard gesture is available to close an app. It can be done with either touch or mouse; while an app is open, start at the top of the screen, and drag toward the middle until you see the app shrink and center on the screen. Then continue dragging to the bottom, and the app will be closed.
Windows 8 apps are “chromeless.” That simply means none of the border cosmetics in earlier versions of Windows are present. Windows 8 apps have no sizable borders, no title bar, and none of the ...