This book is part introduction to, part reflective examination of, the idea and ideal of effective altruism. Its aim is to examine the question: how can we best help others? A question that in turn forces us to contemplate what helping others, effectively or otherwise, really entails. Here the book argues that the greatest help we can provide is to reduce extreme suffering for all sentient beings.
I usually recommend Magnus Vinding’s Effective Altruism: How Can We Best Help Others?, sometimes even to people not new to the EA ideas: the ebook is short but dense and available for free.