Hi Charles,
To put in a picture into your sig do the following
Go into Update Profile and in the Signature: Text & Graphics Version section insert your graphic and nifty quote if you have one.
To have an image show up it must be retrieved from a web site, not your PC. I use a free service called Photo Bucket http://www.photobucket.com. Once you have your image on a website insert it in the form
Once your done hit the preview button to admire your work.
Just a note, don't make your image to large as it will take us poor dial-up users an age to load.
Hope this helps
Darren