If you plan a schedule of events and book signings, it is possible to include a subscription list option on your website where visitors can sign up for regular newsletters and updates on your marketing activities. You will be emailed the contact details of anyone who subscribes.
By encouraging people to join your subscription list, you will be able to compile a valuable marketing list of email addresses - people that you know are interested in your work and publications. Please note that such lists are covered by the Data Protection Act. You will need to provide an 'unsubscribe' option so that people can remove themselves from the list. There are various ways you can get people to subscribe. The simplest way is to include a form on your site where visitors can add their name and email address. If you have a large number visitors with many subscribers, it is worth considering using professional mailing list management software such as Mail Chimp.