In my specific case, I'm looking to promote this skills in children from 5-13 years of age, of a low socioeconomic context, to drift them away from later substance abuse that is problematic in the place they live.
I would start with Arnold Gesell, Jean Piaget and other great psychologists who studied child' moral judgment. Without a good knowledge o the child psychology, how would I educate them. Also, I do not think that "skill" is the right word though is very used by the today utilitarian psychology. We talk here about the good and bad and the discrimination capacity of the children and teens. I would use a lot of dramatic play, stories, some literature (as ' Cuore' by de Amicis, 'Pinocchio' by C. Collodi, some of Gianni Rodari writings, Dickens- Oliver Twist, discussions on some Panchatantra stories), . Also, a lot of activities useful for each other or other people and for animals. lots of group activities but not forced as cooperative projects. And no preaching, just compassion for the people being in bad situation (including perhaps their own parents), and a lot of love. Children in the situation you have described need not so much skills but therapy (a warm understanding) because they already have very bad experiences.