Not a whole lot to it...you use positive rep (I approve) for things that people say that you like or agree with. You use negative rep (I disapprove) for things people say that you dislike. Negative rep isn't used nearly as often as positive rep, but if someone offends you or pisses you off enough, a lot of people will use it. If I find something extremely distasteful, disrespectful, or disgusting I will neg rep.
Caught up. Feeling MUCH better today, woot woot!!!