Super Resource for Non-Profits

At Idealist.org you can find jobs, internships, events, and volunteer opportunities at over 55,000 non-profit institutions all over the world. There's also a huge resource section with tools for nonprofits, a kids and teens center, an on-campus guide, and a guide for teachers on how to begin service projects with their students. The site's also available in French and Spanish, and has a thriving online community with searchable user profiles.