Ugh, okay.
Dummie guide to having a signature!
1. Go to:
www.photobucket.com
2. Register an account and log in
3. Create a new folder to store all your signatures in (if you want to)
4. Upload the signature into the folder
5. Grab the [IMG] code from the bars underneath the uploaded picture
6. Go to the Oddworld forums
7. Go to Quick Links > Edit Signature
8. Paste the code you copied into the signature box
Voila! One signature.