To take a screenshot on your iPhone, iPad or Android, click the Power button and Home button at the same time and then release them, as though you are taking a picture.
If on an Android with no Home button, try the Power button and the "volume down" button instead. If on an iPad with no Home button, try the Power button and the "volume up" button. In both of these cases, remember to push both buttons at the same time and then release quickly, as if taking a picture.
The image will be saved to your photos, where you can then email them to email@example.com.