Oh hreenleaves, I can teach you its super easy

on your keyboard you should have a button that says "PrtScn". usually its up by the F12 key.

Press it once when you are on the screen you want to take the picture of.

Now, open Paint in windows. Open a new document, and go to Edit > Paste on the menus.

Cut out the part you want, or save the whole thing if you want the whole thing.

Next, go to www.imageshack.us and upload the picture. It will give you a bunch of funky looking urls. You want the last one in the last box at the bottom of the page, should say "Direct link to image" or something like that.

Copy it, come back here, and use the image command when you are typing a post. Its off to the right of the text box. Click image and paste the url!

now submit and it should be there.