Depends on what you want to add? You can add a pic that's only seen here on your profile, you can add some About Me info (on the tab next to visitor messages). Your title defaults to how many posts you've made, so you can't change that. You also can't have an avatar shown on posts... Was there something in particular you want all to see? Your signature is added on the Inbox screen. Hope that helps?!
Oh, thank you! That's very kind to say. I still have so much to catch up on. It's amazing just how many items we have in CS isn't it!