Do you have a photobucket or anything like that? Its easier if you use a photo posting site and use the links they give you to post pictures. You can also use a social networking site and get the URL from the picture and use this site
How Do I Add Pictures to My Posted Messages? - and under the first paragraph bullet 2 you will see the HTML to use. Its sorta hard to explain that is why I didnt speak up before. It is the "< img src" one. Thats what I use.
Under the "file location and name" is where you put the pictures URL.