Check out the below resources for TK and Preschool...
Starfall Education
Scholastic Learn At Home Resources
Mystery Science Lessons
Go Noodle
Number Activities
Storyline Online.net
National Geographic Kids
Lexia Parent Resources
Second Step Lessons / Resources
ABCya.com
PBS Kids.org
Sesame Street.org
Unite for Literacy Website
Storyplace.org
IXL ELA/Math Learning
Khan Academy Kids
My Capstone