For taking the screenshot, start the screenshot program. Here we use KSnapshot, but any other program will work until it saves the taken shot in a lossless file format, e.g. PNG. Almost surely you won't find a program without this capability.
KSnapshot dialog
You should arrange the program window appropriately, e.g. by making it as small as possible but yet showing everything needed for your explaining picture. Screenshot programs do normally have settings for
preselecting the snapped area. Set this to "selected window only" as you normally only want to have the window of your program.
activating a delay between pressing the "Snap!" button in the program and the actual snap shot moment. This is useful if you have to open dialogs or do something else in the window-to-be-snapped.
After having prepared everything, start the snapshot process. Most snapshot programs will remove themselves from the screen while the delay is running so that you have enough space to arrange the items to be snapped.
If your snapshot has been taken, the snapshot program normally somehow shows it on screen. Take a careful look on it: Is it ok? Does it show everything needed? Are there any quirks you better do not want to have in the result? This shot is the starting point for your documentation part. As often, the final result normally cannot be better than this starting point. So, make it as good as possible.
Original screenshot for the settings dialog
Our example screen qas quite simple to arrange. A project has to be loaded and the menu is open. Furthermore, the menu item in question is selected. Note that screen shot programs often do not include the mouse pointer. If you absolutely want to have it in your final picture, you will have to put it in afterwards.
Originally, our screenshot includes the complete program window of the HelpSetMaker. However, as everything interesting happens in the upper left corner of the program frame, we'll normally restrict the pictures in this tutorial to that range of the picture.