Blackwell Museum at Northern Illinois University - Dedicated to promoting interest in the history of American education. It's One Room Schoolhouse display has some interesting and useful information.
Clarke Historical Library at Central Michigan University - The Clarke Historical Library collects historical curricular materials and this website has some useful links to sites that will be of interest to those who are researching historical curricular materials as well as those interested, in general, in the history of American education. Under the Resources tab, for instance, there is a link to a bibliography of children's schoolbooks.