Thanks for nudging me on this one. It needed to be done and I think it is now functional.

How to edit your Forum Signature:
Navigate to your Profile Page
Select Edit Your Profile
You should now be able to select your Forum Preferences

You can change three things:
How you view the forum
Age preference of your view
Forum Signature

Edit away and give me some feedback. Right now it should support text and links, which is what most people are after.

You should also be able to view what you have selected in a tab for quick reference.