To set up a "signature," log into the website, then look to the right top corner of your screen for a link, “Settings.” Click on it.
Look down the left navigation bar for, “My Settings.” Just below that, you will see links to edit Profile, edit Signature, and lots more.
Click on "Edit Signature" and add the information you like.
Remember, Signatures only show up in the first post you make within a thread.
Does this help?