Georgia Milestones Practice & Homework Help
RIF Reading Planet
Miss Spell's Class
This site requires a subscription to access most resources, but it offers free videos/activities as well.
This website has rap videos that help teach different concepts in Language Arts, Math, Science & Social Studies. It also requires a subscription to view most of the videos, but some videos may be viewed for free.
Online Math and Language Arts practice games for K-12.
Here are lists of helpful websites (and practice tests)