www.mrsperkins.com (--help with sight words: at the top click on words, select Dolch Word List, scroll to the pre-primer word ist, click on the yellow microphone.)
www.ixl.math (--helps with math: click on kindergarten, scroll down to a section such as C called "Numbers and Counting up to 10." Next, click on the desired skill.
www.starfall.com (--helps with kindergarten curriculum in general)
www.readinga-z.com (--helps with reading skills)