Linked here are collections of job sites created by Nick Martin and PCDN. Nick’s is categorized by “area” while PCDN’s is a menu of social change sites. Both are worth your look. And here is a site for just some “cool” jobs!
Also, not included in each is USAjobs.gov, you are looking for federal work!
Also, consider Paxity, the newest site in the peacebuilding field.