First, find the picture you want. Then in Internet Explorer right click on the image and select "Properties". From our gallery, that would give you a nasty looking URL like: http://www.houseofmulhern.com/gallery2/ ... alNumber=2
Now, paste your URL in the message. Next highlight all of the text of the URL. Lastly with the text highlighted, click the Img button above the box where you type your message. That will put tags around the URL designating it as a picture.
Then click preview and you should see something like this:
You can link in pictures from any website this way.