Scheduled Reminders / Emails

Hey, i am not really sure the best way to describe what i want here, but i can tell you want i need to do..

basicly, i want to gather user infomation during the account creation process, including how often they will need remiding / due date

and have an automatic email produced including a standard message to users on there selected date

what is it im looking for? is it out there? haha I am sure there is something i could use, but my minds blank

thanks for any advice in andvance