There is a new site for free online math and science classes for grades 6-12, plus some. This site provides open source text and work books, excellent for the homeschooled student.
The site is new, but this video will explain where it is going.
Introducing CK-12 Foundation's Digital Learning Tools - #2 from CK-12 Foundation on Vimeo.
~posted by Andrea from Notes from a Homeschooling Mom