You can have a page where people will be invited to sign up to your newsletter, like the page we have here. If you do, we recommend Aweber if you want to use a simple, well supported newsletter provider.
All you have to do is sign up for an account at Aweber, MailChimp, GetResponse, iContact, ConstantContact, etc, build a form and then paste the code they give you, replacing the sample Aweber form above.