To take a screen shot on your iPhone you first need to Turn on the iPhone and navigate to any screen preferably a Web page, any application screen or email. If it shows on the screen, you can photograph it then locate the Home button centered under the screen. Check out the link http://www.ehow.com/how_4800865_screenshot-iphone.html for detailed instructions.
Try holding the top right button down and then pressing the circle button with a box in it. The top right button must be held down the whole time. That is how my phone works. You will find it in you pics. Hope this helps.