Easy Peasy All-In-One Homeschool - online home education, put together by a Christian missionary who made it available for free because she doesn't want anyone to not be able to homeschool because of time and/or money. It's set up so the parent doesn't have to do a thing (the lady has like 8 kids so can't!). It covers everything: art, history, Bible, reading, spelling, etc.
Paper Rater is a webtool that offers a robust grammar checker to find mistakes and correct them. It can also check to see if a students paper contains plagiarized text. This is a wonderful tool for the classroom and it is easy to use as well.