If it says you are mistyping your handle your password, then that tells you all you should need to know. Remember that the password is case-sensitive, and remember that if you are pasting it directly out of the e-mail, not to paste additional spaces at the beginning or end. If that still does not work for you, you can use the Lost Password feature on the main page once every 24 hours to have a new password generated for you.
If you are not receiving an error message at all, please read the relevant sticky thread posted in this forum.