Increasingly we are being asked how individuals can assert or register copyright in their work. Assuming that you are not publishing with journal or book publisher (or on a recognised web site, etc.), you will retain all rights in your work. In the UK there is no need to register copyright. This is because it automatically arises as soon as a work is recorded in a perceptible format, e.g. a written manuscript, a photograph, work of art, etc.
You may want to identify a work as your own by using the standard copyright symbol © followed by your name and the date the work was created. You may also want to consider applying a Creative Commons Licence to your work to make it clear what types of re-use you will permit.
Commercial services to register copyright do exist. However these services will make a charge to do something that UK Legislation does for creators automatically. The Author’s Licensing and Collecting Society do provide some suggestions of how you might want to ensure that you have proof that you are the creator of a work should there ever be any legal issues: http://www.alcs.co.uk/Authors–rights/All-about-copyright/Registering-copyright