Interesting question - in part because your notion of meta-ethics is quite different from mine. You want meta-ethics to answer the question "What ought I to value?". That is an important question, but it is not usually understood to be one of the central concerns of metaethics. But since ethics answers the question "Given my values and those of people around me, how ought I to behave?", it does seem that the "What ought I to value?" question is in a kind of meta- relationship.

This is one book that tries to answer the "What should I value?" question. I thought it was pretty good. Philosophy, but not modern analytic philosophy. I don't know that I would call it naturalistic, though. (The cartoon version of its answer to the question: "You should value as little as possible - try to shed your desires.")

Three books on naturalistic ethics that I have read are Gauthier's "Morals by Agreement", Binmore's "Natural Justice", and Nozick's "Anarchy, State, and Utopia". All three are excellent, though the third (and to a lesser degree, the second) focuses on "macro-ethics" issues of what society ought to do, rather than the pure ethical issue of what you ought to do to others. (No one seems to focus on the micro-ethics issue of what you ought to do concerning yourself - that is a bit of a shame.)

Another recent book on naturalistic ethics that I have not read is Sam Harris's "The Moral Landscape". Harris is well known as one of the leaders of the "Gnu atheists", and the book has been much reviewed in the blogosphere. My impression is that it will be a decent read, but will waste time talking about God (i.e. how Harris sees no need for that hypothesis), when what you want is talk about ethics.