From the list of available classes at your school for your book's Supersite, look for your teacher's name. If more than one class is listed for your teacher, you may click the information icon in the last column of the course listing for more details.
Select your teacher's course by clicking the radio button for the correct class in the list.
Click "select course" to enroll.
Look for a flash alert on your Home page that confirms you successfully enrolled in your teacher's class.