Best of History Web Sites is " an award-winning portal created for students, history educators, and general history enthusiasts"; sites are rated for usefulness and accuracy
History Matters: "the U.S. survey course on the web". Designed for high school and college teachers of U.S. history
U.S. Department of Education has some good U.S. history resources for schoolteachers https://teachinghistory.org/
Genealogy for kids: article on how children can participate in genealogical research, with links to helpful sites
A teacher's guide to the Holocaust: An award-winning site about the Holocaust, packed with information, photographs, movie clips etc.
A visual sourcebook of Chinese civilization: designed to add to the material teachers can use to help their students understand Chinese history, culture, and society
The British Museum has an extensive site on ancient Egypt