If you use Gmail or have a Google account through your school, you can use that account with Quizlet to sign up and log in.
Teachers -- this is a great option for getting your students using Google Apps for Education signed up for Quizlet quickly.
Signing up with Google
First, go to the Quizlet homepage and select Sign up.
Then, select Sign up with Google.
Enter your Google username followed by your Google account password if you aren't already signed in.
Select Allow to grant Quizlet permissions to view your email address and basic profile information.
Enter your birthday, and Quizlet will automatically generate a username for you based on your e-mail address. If you don't like that username, you can enter something else on this screen.