ticker
HI Patti Jo,
You want to go to a place like www.tickerfactory.com Create the ticker that you want and then once you get to the end, copy the picture of the ticker (NOT the code).
Come back here and click on the User Settings link on the left hand side. Find the section near the bottom that says Signature. Copy the picture of your ticker into the box...you can also type whatever you want in that box as well.
Make sure to check the box that says Enable Signature and then hit the save button. You should be all set.
Good luck!