Hi Hawkeye,
To upload to the Forum, you need to start an account with Flickr or Photobucket. Once you have that and uploaded your images to it, copy the DIRECT LINK:
Now, back on the Forum, click the USE RICH FORMATTING option at the bottom of your message box:
Type your message. Then, when you're ready to insert the image, click the IMAGE icon in the tool bar:
Enter the link you copied earlier into the dialog box and voila! You image should appear in message.
Good luck!
Tim