Reading:
*PBS Kids: AlphaBricks
*PBS Kids: Alpha Pig's Match Up
*PBS Kids: Lovely Letter Match Up
*PBS Kids: Rhyme Time Bingo
*PBS Kids: Lickety Letter Bingo
*Starfall
*ABCya
Math:
*ABCya
*MegaMath
*Turtle Diary
*Primary Games
*iTools
*Counting Rhyme: One, Two, Buckle My Shoe
*Kindergarten Math Skills Practice (HUGE list of links to practice various math skills)