Welcome to the board stymee!
First you must host athe picture(s) on a web server. I like to use ImageShack but there are many more. Most will provide a link that you copy & paste into the body of your message. It's really pretty simple. Here is a tutorial that will help: http://www.barbecuebible.com/board/viewtopic.php?t=5817
If you have any questions, do hesitate to ask.... We love pictures.