Go to turnitin.com and select create account at the top of the page. At the bottom select student from the list. Enter the class id and password for you class. Fill in your name, e-mail address and create a password. You'll also have to have a safe question and answer. Click the button that says I agree and you're in!
Class ID Password
Per 6: 18996040 Aeta
Per 7: 18996049 Zulu