ok, first off, when you create an account, it might actually store it in a 'temporary' database until the account is 'authenticated'.. The reason for this, people create accounts just to get around a ban, or something, or maybe to take up space, just to be annoying really... so the verification system put in place, they'd have to create an email account, then verify it when the code was sent to them...
As for how do you get it to redirect someone? simple, use header..
header("Location: http://www.google.com");