Use the same username and password combination you use to login to the school computers. You can change your school login password by logging into any computer on the CBHS campus and hitting ctrl-alt-delete at the same time and choosing "change password".
You do not need to include @cbhs.org or cbhs\ in the username. Your password must be at least 7 characters long. If you have any trouble logging in or need your password changed, email email@example.com.