If you let your browser have cookies, than at the user login section (right most of screen) you should see your username and something like this at the password box ********. When you see these filled than you just have to press the "Log in" gray button.
If you don't let cookies than you will have to retype both fields each time.
If for some reason you cannot login, click theRequest new paswordlink, than by providing your username or email address you will be notified by email for a new password.