A lot of material has been developed on how we can go about doing a lot of good. Here is some of the best.
If you like TED talks, watch Peter Singer’s The Why and How of Effective Altruism. The Life You Can Save (Singer’s first book on Effective Altruism) in 3 minutes is a great watch.
A great place to start is this introductory list on the EA forum. Ryan Carey has also put this in a more detailed pdf format.
Ben Kuhn compiles a great set of articles here.
A good primer on GiveWell, global poverty reduction (and charities in general): Giving 101: the basics
Peter McIntyre write a post summarising charity selection heuristics, and some cause areas: Effective charities 101
How should you spend your 80 000 hours of your working life? 80 000 Hours (where did they get the name from?) has put together an incredible guide on careers.
Singer’s books: The Life You Can Save, and The Most Good You Can Do are good introductions, and have changed many people’s lives.
Will MacAskill’s book, Doing Good Better, will be published in August 2015 and is sure to be a good read.