To create an account (sign up) go to http://mailman.cchmc.org/ and click the sign up button.
Enter in your information:
!!!!!!!!!!!! Do not use your CCHMC password for this system, a separate password should be used.
You will see this screen about a confirmation email
Go to your inbox and find the confirmation email.
After you click on the confirmation link, you will be taken back to mailman
Now you can sign in.