I want a signiture in Mozilla Mail but even after followin these instructions it still dint work. What else do I have to do??

I don't know why you're following the guide for redhat 7.2 when you're using rh9. I also don't know what version of Mozilla you're using, but in version 1.4 you have to tell Mozilla what file to use for your sig. So, in Mozilla Mail, click on 'Edit' in the toolbar, then 'Mail & Newsgroups Account Settings...', then under the boxes for your name, email, reply-to, and organization; you click 'Attach this signature', and right below that click the 'Choose' button & navigate to the sig file you already created (though I'd move that to ~/.mozilla/ just to keep things tidy)

Enjoy!
--- Cerbere