Please read the Elements of Moral Philosophy chapters on
Ethical Egoism (and poverty) and
two chapters on Utilitarianism (euthanasia, drug use, treatment of animals).
Please read "The Singer Solution to World Poverty," from the NY Times, and in The Right Thing to Do, and/or "Famine, Affluence and Morality"
Please read John Simmon's "Reasonable Humans and Animals" (also, here)
Please read Peter Singer's "All Animals Are Equal" (also in RTD)
And, finally, Michael Huemer's "Unjust Drug War" (also in RTD)