New users are welcome to use the RTOT course site. If you are enrolled in a college course (you know who you are), choose your college from the list at the left. If you are an independent or unaffiliated learner, the Open Course -- "open to anyone" -- was built for you.
To get started, just choose one of the course links, and you will be taken to the registration page. Fill in the blanks to set up your user account. After you get the confirmation email, which comes in a matter of minutes, click on the link provided, and you're in.