Unicef’s Global Classroom provides lesson plans, games and educational resources for both students and teachers in elementary and secondary school. UNICEF incorporates both international and environmental issues into their educational resources which have become popular tools for many teachers. Find classroom resources on the Unicef website.
CHF has a global educational program that prepares teachers with a wide range of resources surrounding issues like hunger, agriculture, and global citizenship. Their website has several lesson plans organized into topics and grades (from grades 1-12). There are also videos and presentations for all ages. You can find these resources on the CHF website.
Oxfam in the U.K. has created 11 lesson plans and resources explaining basic human rights as they relate to those who are disenfranchised and who live in poverty. This very good summary of human rights is ready to be used within the classroom, with simple explanations and basic terminology. The site expresses human rights in a manner which can be grasped by most middle level students. Here is the link to the Oxfam website.