Here is a how to from another post
courtesy of Meg
The easiest is to create an account with Photobucket where you can upload your pictures.
http://photobucket.com/
Once your pictures are uploaded,
1. select a picture
2. click on the img code under the picture(this copies the image address)
3. go back to the posting window here and click on the Img button above the posting window, paste your picture, then click on the *Img button
4. clicking on the preview button lets you see if it worked
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