New updates are posted every Tuesday, and are available to students currently enrolled in the exam prep class. You need to know the edition of the book you have, along with your book number to access the update.
If you have a 20th edition book:
Your user name is student20
Your password is 2011 followed by the first two digits of your book number.
For example, if your book number is 400152, enter 201140 for your book number.