So if anyone wants to create/update their signature line:
Click on your avatar in the upper right hand corner.
Select "Edit profile" from the dropdown.
Update your signature (and any other info you might want to add, like your website).
Be sure to scroll down to the bottom of the Profile page and "Save changes".
You can also change your Picture if you don't want the default icon of the first letter of your user name.
Click on your avatar.
Select "Change Picture"
Upload your picture, either from your device directly or from a URL. I decided to keep my WTF avatar of my pup Maggie, so I just logged into the original WTF and did a "copy image link" of my pic over there.
Save Changes.
I've added a link to this thread in the Tips , Tricks and How-Tos thread.