The website Open Learning Initiative is exactly what its title suggests. It is a website dedicated to open learning. There are free courses, which you can follow, or even 'peek in', as they say on the website. These courses are available to anyone, and your progress is not shared. You can create a free account and 'join the class' of a particular course, or ou can just peek in, which doesn't require an account. Among the free open courses, biology, argument diagramming, chemistry, media programming and French can be found. The website can also be a way to create your own course for your class, and share it with your students, but this doesn't apply to me, so I don't know much about this aspect.
I made myself an account and started the Biology course. It is quite extensive, and covers things that are much more detailed and therefore complicated than an ordinary highschool level. But do not let that scare you away! It is very interesting, and there are other things than Biology. This website is a good free (I cannot stress this enough) tool that is valuable to little home-schoolers such as myself. I did the first lesson in the Biology course, and it starts with the most basic of introductions: cells. So now I know that a nucleolus is inside a nucleus, and that those two are surrounded by the Endoplasmic Recticulum. The only problems I see with this website are that there aren't many free courses for the moment, but there are many different subjects planned, so this won't be problem for long. The last, but certainly not the least problem, is that the website doesn't work on Chrome, the browser I use. Many of the animations used in the lessons do not show up. In order to continue the course, I have to use Safari, which supports all the animations.