I'm with SetterNut in that I use photobucket. You have to create an account on a 3rd party website (photobucket for us, there are others). Upload your picture to your library there. Then if you click around on it enough you'll see some code that looks like this below (from setternuts reply above)
[IMG ]http://i935.photobucket.com/albums/ad191/setternut/Feb14_263.jpg[/IMG]
(note, I added a 'space' after the first IMG of his link to break the code so it would post as text rather than the picture)
[IMG ]followed by the web address your picture is at[/IMG] is what prompts a bulletin board to insert the picture