This online learning system has courses for nearly every subject and all grade levels (even offering college credits!) Materials include video lessons, and online quizzes and tests. You can track progress for as many students as you'd like with the teacher subscription, which is reasonably priced at $60/month.
Saturday Grab Bag
Printable curriculum materials for preschool through second grade levels.
Thursday History/Social Studies
This website from the Government Publishing Office has resources for learning about the US govern
The name of this site says it all!
Tuesday Language Arts
This company provides programs for beginning reading and math learning.
This company publishes three books for helping elementary learners explore science.
Self-paced, online courses for learning coding.