Christianbook Distributors offers a lot of homeschool curriculum and supplies. They offer all grade levels and subjects. Any time you want to compare a few different types of curriculum, this is an easy place to do it.
I like to use them for some of the extras like spelling, grammar, etc.
Khan Academy offers videos that help teach your child. They offer a way to grade assignments and tools you need to be sure they are on the level they need.
Affiliate links are used. Any purchase made is a blessing to my family at no extra cost to you!