How to to send automatic newsletter to addresses signed up via my site?

I want to start a newsletter that will go out every month to people who have signed up for it via my iweb site. Is there a way to do this? Basically what I want it a text/search style box that lets them enter their email address and click sign up, then store it in my address book in a certain group so I can send out the newsletter. Also would it be possible to get an automatic verification email sent?

Thanks