There are many ways to get people’s email addresses. The easiest way is to simply use the same contact form that is on your Contact Us page. The problem with this method is that you now have to take that person’s name and email address and enter into your mailing list software or email program. You will also have to manually deal with superscription requests. The CANSPAM act requires unsubscribe links in every mass mailing.
A better way would be to use the Newsletter feature that I have included with your website. For more information about this newsletter software or a better (but more complex) option go to the NFT Support page.