Wikipedia's metaethics article might be a good alternative starting point -- lukeprog's article does not add too much to that I think.
Anyway, meta-ethics tries to figure out the ways to determine the actual values of 'variables' like right and wrong in first-order ethics.
Personally, I don't think there is any objective way to determine this; meta-ethics can concern itself with the question whether any proposal is logically consistent but cannot really determine the answer. Morals are a human invention and I can't see how one could ever prove anything -- there are only our intuitions.
Similar to things like free will or purpose in life, ethics seem merely like a useful illusion.
lukeprog gave a list of metaethics questions here:
Most of these questions make no sense to me. I imagine that the moral intuitions in my brain come from a special black box within it, a "morality core" whose outputs I cannot easily change. (Explaining how my "morality core" ended up a certain way is a task for evo psych, not philosophy.) Or I can be more enlightened and adopt Nesov's idea that the "morality core" doesn't exist as a unified device, only as an umbrella name for all the diverse "reasons for action" that my brain can fire. Either perspective can be implemented as a computer program pretty easily, so I don't feel there's any philosophical mystery left over. All we have is factual questions about how people's "morality cores" vary in time and from person to person, how compelling their voices are, finding patterns in their outputs, etc. Can someone explain what problem metaethics is supposed to solve?