Works are copyrighted upon creation in a fixed, tangible form. Registration has some advantages but is not required. If a work is published by a mainline book publisher or a journal, the publisher may take care of registration for the author.
Note that the average processing time for copyright registrations filed electronically is 9 months.
You must file in paper for the following formats:
Mail the form, the fee, and the deposit copies to:
Library of Congress
U.S. Copyright Office
101 Independence Avenue SE
Washington, DC 20559