We are regularly asked how to copyright web content. The best source of United States Copyright information is the Copyright Office web-site. You can register on-line literary works or writings for the cost of $30 U.S. While you can register a copyright for your web-site content, you CANNOT copyright your domain name.
While you can register your copyright, and gain several rights (statutory damages, attorneys fees and prima facia evidence of copyright to name the biggest of them) from doing so, you don’t need to to be protected. You are automatically protected on publication if the work is unique and your own. Even non-United States parties may be protected by U.S. copyright laws if their country of domicile has reciprocal agreement (see pdf formatted list of such countries) with the United States.