Great overview videos like this one on the not so dark "Dark Ages."
"The Smithsonian Learning Lab is a major rethinking of how the digital resources from across the Smithsonian’s 19 museums, 9 major research centers, the National Zoo, and more, can be used together, for learning."
SHEG has terrific lesson plans and resources for historical thinking skills, such as Reading Like a Historian.
"The Reading Like a Historian curriculum engages students in historical inquiry. Each lesson revolves around a central historical question and features sets of primary documents designed for groups of students with diverse reading skills and abilities.."
Offers a powerful, innovative model curriculum for teaching world history in middle and high schools:
"World History for Us All is a national collaboration of K-12 teachers, collegiate instructors, and educational technology specialists. It is a project of San Diego State University in cooperation with the National Center for History in the Schools at UCLA."