khanacademy:

For years now we have been getting requests to offer a complete Calculus course on Khan Academy. In an effort to create a course of the highest quality by Fall 2014, Khan Academy is partnering with Phillips Academy Andover.

We are working with Andover’s math department (30 teachers) to develop rigorous adaptive exercises appropriate for a first-year course in Calculus. We just started adding questions to our site and will continuously add content throughout the year. Read more about the partnership here.

Try one of the first problems here.