Harmony Art Mom has some great art and music plans too, Hers aren't all free but they are reasonably priced and well done. There are many free things on her site that are not to be missed. She has the best posts about homeschooling high school.
Barb who does #5 also does the Handbook of Nature Study blog too. Hands down the best nature blog out there. She makes doing nature lessons a no brainer.