Now, it could be everyone else already knows this, but I just learned how to do it today, so maybe there are others out there who need the info!
I often need to grab a screenshot to help readers visualize what I'm writing about. For example, this post the other day on Flipboard. I needed a screenshot, figured you could do it, but didn't know how. Well, turns out it's easy. (Thank you, Apple!)
1. Hold down the power button at the 'top' of the iPad.
2. While holding down the power button, quickly press the screen button at the bottom of the pad. (Don't just keep holding it, you will start the shutdown process! I learned that the hard way.....).
3) Your screen should flash once, and you'll find the screenshot in your Photos app, which you can then email to yourself if you want it on your computer.
Easy-peasy, huh? Works on the iPhone, too.