Intro to Naturalist Metaethics?

Can anyone recommend a good primer on naturalist metaethics? I’ve read the Fun Theory Sequence, and found it fascinating, but it only deals with fun. There are also life, death, pain, torture, and possibly other goods & harms to consider. Also, the Fun Theory Sequence tends to focus on macro-metaethics, i.e., what would be best for all of us to do together? I would also like to learn about micro-metaethics, i.e., what should I do with my life, and how should I choose which parts of myself to emphasize, or which parts of myself I will think of as “really me” or “the best part of me?”