Haha! Yes I can! (sorry, I just figured it out since I didn't know...) ok, you see in your upper right hand corner, where you see your signin name of "butterfly" yes? well, right next to it is a tab that says "edit" click on that
It will bring you to your bd profile page. At the top are 3 new tabs, click on the one that says "site options" at the bottom of this page, is text box for you to type your signature in. don't for get to click the SAVE button below when you have it as you like it!
Hope that works for you and that I wrote it so it was easy to follow!
Lois