I am not a forum newb at all, and I cannot find a way to add a signature to my posts. It is obviously something that can be done, as other have them, but when I looked at my profile options, I see nothing related to signatures! I wanted to add my custom banner for my Loki cosplay so I don't have to keep repeating myself.....

If you go to your profile, and then edit profile on the right hand side, you'll be greeted with ways to change your profile. Clicking on Account Settings you change your profile pic and further down there is your signature.

And obviously, if you clicked on banners on the top bar, you can make a bar to put certain cosplays for events in a bar that you can copy the code over into your signature to let everyone know.

Hope that's somewhat helpful. xD