Back in 2011, I wrote an article that provides a list of free online high school classes that can be used to build a college prep course of study. The checklist of courses is based on North Carolina's requirements (similar to other states) for students to graduate with a public school diploma. But it also serves as a valid guideline for homeschoolers who want to go on to college or university, as these institutions want to see certain requirements fulfilled in high school.
I tried to list mainly those sites with complete courses, in other words those with lessons, course materials, and assessments all presented as single, in effect, electronic curricula. It's a good list that breaks the information down into all the core subjects and electives. (You can read the article here. I also wrote a Kindle e-book of similar content you can access here).
I've had to continuously update it, since there are so many new sites and courses that become available all the time. At first, I was doing the updates at the article itself, but it's a bit cumbersome. Now, instead, I send out a free monthly newsletter highlighting the new stuff I find. You can read my past newsletters in the Archive and sign up if you want to receive them.
Here's a sample of resources culled from the past 8 months or so of newsletters:
MOOCs - Can't talk about free online courses these days without mentioning MOOCs (Massive Open Online Courses), being offered by many prestigious universities. (For a brief overview of MOOCs, watch this video).Three established companies providing platforms for these courses are Coursera, edX, and Udacity. For additional sites, click 200 free online courses, many of which offer certificates or statements of completion.
Algebra 1 - Visit SAS Curriculum Pathways, subscribe for free and access their complete Algebra 1 course.
English 10 - Head over to Curriki for free access to a large and growing library of curricula and individual learning units. Here's a full course for 10th grade English.
Biology - Exploring the Way Life Works is an online textbook with eight downloadable chapters. Visit the companion website and you can access assignments, activities, PowerPoints, practice tests, and additional links.
Personal Finance - This Financial Literacy Curriculum is comprised of 22 lesson plans and accompanying teachers guides that can be downloaded separately, or altogether as a zip file. The lessons are free, but registration at the site (also free) is required.
For additional high school links, visit the Homeschooling High School Newsletter Archive.