Keeping in mind I know almost nothing about the NaNo website...

I forgot my NaNo password and was able to reset it using the link to something like "Forgot Password" on their login page. Now, there are like 3 different ways to sign in to nanowrimo, and I can't even make a suggestion for it if you used the Google or Facebook signup links. But if you use the username/password fields, then down below that is a "Forgot Password." If you select that, you can enter the email address you used to sign up. A link to reset the password is sent to that email address. Check that email address and something should show up in less than a minute.