Super Teacher Worksheets is loaded with all kinds of free printables. There's every subject imaginable there! States and capitals, counting money, decimals, algebra, phonics, reading comprehension, grammar, etc.
Also, if you're working on Scripture memory, here's another place for more printables in the NKJV.
And this is one of my kids' favorites! At FreeRice.com, you can answer math, vocabulary, and other questions and with each correct answer, they donate 10 grains of rice to World Hunger.