How do you copywrite things on your blog?

I have a blog on blogger that I post ramblings and original poetry on. My blog is open to invited readers on but still I don't want anyone stealing my work. I notice that other blogs have "copyright" warnings on them. Is this something I can just add to my page? How "protected" am I with the warning?

Copyright or not. They'll take it.

If you don't want it taken...Don't put it on the web.

you need to get with a programmer and they can help you protect it