Non-profit with free research on where donations do the most good, plus a public pledge community and evaluations of charities and causes.
From the site: 100x your impact by finding and donating to the best charities. Learn about high-impact philanthropy, join an effective giving community, take a giving pledge.
Why I recommend it: Their cause research is a good model of reasoning under uncertainty, whether or not you pledge. Nothing is paywalled.
A comprehensive nonprofit education platform offering live and on-demand webinars on fundraising, grant writing, marketing, board development, and nonprofit management.
Why I recommend it: If you are launching or leading a nonprofit, CharityHowTo fills a practical skills gap without the overhead of a degree program. Their grant-writing webinars are especially useful.