How do you turn off the CLICK sound on your iPad 2 when you take a screen shot/ picture

Use the mute function, which depending on how you have it set up, is either the toggle switch on the side just above the volume switch, or the control in the tray (double click the Home button and swipe to the right. It's the last control on the left.)

Note: you can set the function associated with the side switch in the Settings app, under General. Whatever setting use assign to the switch, the other will be in the tray.