If you think well of Hillsdale College, they have a K-12 Curriculum available on their website free of charge.
DonnaYoung.org is free and the best site for record keeping resources. Learner.org has high school/college level courses, some of which are completely self-contained.
If you live in California I can give you more advice, since there are some state-specific rules.
Also, some community colleges will allow high school students to be concurrently enrolled. One semester of college equals a year of high school on the transcript, and also counts (in most cases) toward an associates and, possibly, transfer to four-year college.