It is not hard. Here ya go...
Hosting your pic:
1. Open a Photobucket account (www.photobucket.com
1a. As far as I know you do not need to fill in the reg form with real information. I think only the email needs to be real.
2. Upload your pic. This is pretty self explanatory when using Photobucket.
Displaying your pic on the forum:
1. Select the Img link listed under your picture.
2. Press CTRL C to copy the link
3. Create a new message
4. Press CTRL V to paste your link into the post.
5. When you view your message, for example using the preview option, you should see your pic listed in your message.