ABC Mouse Early Learning Academy full curriculum for Pre-K through K, two options for paying monthly $7.95 or yarly $79.00 price is subject to change.
Starfall is an interactive site which teaches reading, be aware that there are areas which require payment such as More Starfall along with the Kindergarten curriculum.
PBS Kids be sure to visit the island for reading. Progress tracker, printables and much more.
NBII Kids is an interactive site for children to learn about animals. There are some printables also.