Additionally, many individual writers and other sites have interesting material on effective altruism:
Effective-Altruism.com, where many different authors discuss EA issues and current events.
Giving Gladly, written by Julia Wise: Always original, and very warm.
Reducing Suffering, many excellent philosophical pieces by Brian Tomasik.
The website of Ben Kuhn, leader of Harvard’s student EA group.
Less Wrong, a blog focused on rationality, with a sizeable effective altruist contingent.
GiveWell does extraordinarily rigorous research on which charities and causes will do the best with your money. They make sure that their recommended charities do what they say they do, that what they say they do is effective, and that they have room to use your donation productively.
Giving What We Can is a society of people who have pledged to donate 10% or more of their income to the most effective causes.
80,000 Hours researches how we can choose careers that will have the most impact. They also provide one-on-one career coaching for aspiring altruists.
The Center for Effective Altruism, parent organization of both Giving What We Can and 80,000 Hours.
The Life You Can Save, an offshoot of Peter Singer’s book by the same name, is the largest effective altruist organization. Its 16,000 members have each pledged to donate at least 1% of their income to effective charities.
Oxford’s Future of Humanity Institute uses the tools of mathematics, philosophy, and science to research big-picture questions about the future of humankind, including the altruistic potential of working towards improving the lives of people in the far future.
The Future of Life Institute, similar to the above, but based in the US.
The Sentience Institute, a think-tank dedicated to expanding humanity’s moral circle.
Animal Charity Evaluators – like GiveWell, but focused on the plight of all sentient beings.
The Open Philanthropy Project, an offshoot of GiveWell dedicated to researching and implementing effective philanthropy by high net worth individuals.