Screenshots in-game are easy. You press one key and your shot is saved inside a folder automatically. I didn't even look on how to figure this out until I dinged level 70, since then I have taken thousands of shots.
On your keyboard, typically on the upper right, is a “Print Screen” key. Some keyboards you only need to hit this key. Other keyboards you will have to turn on and off the function key to make it work.
While running the World of Warcraft game hit the print screen key to take an in-game screenshot. When you do yellow type with the words “Screen Captured” should flash on your screen.
If you would like to take a shot without your user interface (UI) that is easy too. Type the keys Alt+Z will hide your UI. When you want it back you type Alt+Z again.
That is it. A shot is now saved.
But where is the image?
In your World of Warcraft program file there will be folder called Screenshots. If everything is at the default places it is at “C:\Program Files\World of Warcraft\Screenshots”.
Within the screenshot folder are jpg files of what was on your screen when the print screen key was pressed.
Now you can modify the image to your delight!
I take screenshots to remind myself of potential blog posts. Sometimes they actually make it into a post, other times it is a pure reminder. I also keep the original unchanged and edit a copy just in case I, you know, mess it up.