Online curriculum for Language Arts, Math, Science and History. Includes video lessons, practice problems, and differentiated instruction. Monthly tuition provides up to 5 courses per student, and students work at their own pace. There are discounts for multiple students. Could be a pretty good deal, if you used it for several subjects.
Free art lessons for elementary ages.
Online reading, math, and spelling curriculum for elementary ages.
Complete math curriculum for jr. high and high school levels.
This subscription site has loads of resources for learning through children's literature.
A website with lesson plans, worksheets, labs, and activities on biology topics.
The website of this museum in Boston has lots of informative articles, videos, and some free less