All authors should copyright their work. A Copyright Notice acts as a deterrent to copyright infringement or, if infringement does occur makes it easier for the author to pursue the copyright infringer.
All of my books, together with the posts on this blog (newauthoronline.com) are copyright Kevin Morris).
When I first ventured into the world of publishing I was somewhat naive regarding protecting my work. I had, of course seen the copyright notices contained within commercially published books. However for some inexplicable reason it never crossed my mind that I should protect my own creations by employing the law of copyright.
Having recently read a number of posts regarding the theft of intellectual property I have determined to correct my omission by including a Copyright Notice with my current (and future) books. Thus far I have been lucky as no one has copied my work. However I and other writers can not work on the basis that everyone will play by the rules and respect our intellectual property, hence my decision.
For a good exposition of copyright as it pertains in the United Kingdom please visit http://www.copyrightservice.co.uk/copyright/p03_copyright_notices.