I receive a lot of e-mail from aspiring authors, mainly because of the popularity of my guide to getting a book published, and to a lesser degree my book publishing glossary (which is actually aimed at a more advanced audience). One of the questions I get most often is “How do I protect my work from being stolen when I send it out to prosepctive publishers?” This is not a question that established authors usually agonize over, and I’ve fumbled around a little bit for an answer before evolving my current response:
In the U.S. your work is automatically protected by copyright from the moment of creation (at present it lasts for your lifetime plus 70 years). Reputable publishers stealing work from authors is rare (less rare is being offered an unfavorable contract after acceptance). If you are concerned, you may discretely place somewhere a notice in the form of Copyright 2010 by YourName, although most established authors do not do this, and you should be aware that doing so can make you appear amateurish. It conveys to publishers the subliminal suggestion that you don’t trust them not to steal your work.
It is possible to register your work with the copyright office for a small fee, which provides significant additional protection, but it is probably best not to mention having done so to a prospective publisher at the time of submission — again, it can appear unprofessional, since it is usually beginning writers who are most concerned about this. For more information see http://www.copyright.gov/help/faq/.
It is sometimes suggested that you could also document the date of your work through taking a photo, sending the work as an attachment in an email, or mailing it to yourself, but I doubt this really accomplishes much. I have published quite a few books, and I have never done this with any of them.
Image from El Mariachi 94’s photostream