Where Can I Get My Literary Work Copyrighted?

I have an idea for a TV show (don't we all) and it's not what you would consider a script by any means. Rather it is just a basic one pager outlining what the show is about and the main and sub charecter list. I would like to have it copywritten so that my idea can't be ripped off from me blindly. I know that a certain form must be filled ot along with a fee. However, I am having difficulty finding the right form to send to the library of congress on the internet which deals with such issues. There are so many, can someone tell please tell me what form I need, a link to it perhaps or the name of it.