Before submitting a game or voting you must create an account. The info you enter is used only for verification purposes and to keep track of stuff. An email will be sent to you upon registration -- just respond to it, and once a confirmation email is sent you're golden.
Your user name shouldn't contain any funky characters -- just letters and numbers and such. The password hint is to remind you what your password is, in case you forget it down the road (the hint should not contain the password itself!).