I would post screenshots, but I don't know how.
If you have Windows, then you have a Print Screen button on your keyboard. Press it to make a screenshot, then open Paint, and crop the image. Or if you're on Mac, press cmd+shift+4, and select the part of the screen you want to make a screenshot of, you'll find the image on your desktop.
Then upload it to a site like
Imgur, and copy the direct link (so that it ends with .png or something like that) and put it in between [img][/img] tags.
If you made quite a large image, adjust either the width or the height of the image like this:
[img width=640]http://i.imgur.com/aaaaaaa.png[/img] or [img width=480]http://i.imgur.com/aaaaaaa.png[/img]