>what are Reputation Points?
A frivolous and pointless feature that nobody cares about.

>And how exactly does this system work?
If you see a post you like, you can give the poster good rep. This increases that person's reputation by a certain number of points depending on how many points you have. The more points you have, the more green bars you have under your name, and people can (theoretically) judge how good of a member you are. Likewise, the opposite is true with bad rep and red bars.

It works like this: People get mad at posts, so they give you negative reputation. I kind of like that though. I'm getting close to having a red bar.

Okay. What's the single star under your ID?

It's just reflective of how many posts you have.

Okay. So how does the star system work? In my case, I've got 212 posts. So I get no stars? Could you point me to where I could find out the details?

1,000 posts is 1 star, 2,000 posts is 2 stars, and so on and so forth ... up to 5 stars - It's really a pretty meaningless statistic. Think more about quality than quantity.