[Locked] Sigs

Alright I've seen alot of people having a pic as their sig and I have no idea what to do to get a pic in there because it just gives me a textbox and says "This is a block of text that can be added to posts you make. There is a 255 character limit." Is it supposed to be some textbox where I just put in some html code like how the posts work? I only just noticed about the sigs after the website when under the big change, so now I want to get a sig of my own in my posts and profile. Oh and if this question has already been previously answered could you redirect me there. Thanks.

[code:1][/code:1]

Oh so it's just links to a pic's location, I see, so adding in the spoiler would work as well like I've seen other users do, well thanks for the help.