That little navbar (on top with Search, Member List, Calendar and Help). I want to add something to it, how would I do that?
ACP > Templates & Style > Templates > Header Templates > it's usually header on most themes but may be header_welcomeblock_member/guest on some > copy one of the other links and edit the appropriate bits.
ACP >> Templates & Style >> Templates >>
yourtheme >> Header Templates >> header
Add a new list item, just copy and paste an existing one and change the details.