Hold the phone facing you. On your left, at the top of the phone, you will see a hole where you would connect your headset. On the right, at the top, there is a short, black bar sticking out slightly. Press down hard on the right side of this bar and release quickly. The Apple symbol will appear on your screen and the phone will turn on.
To turn the phone off, press down on the right side of the same black bar and hold it until a message appears on your screen to slide an arrow symbol from left to right. If you do this, the phone will turn off.