If you really want to copyright your songs, go
http://www.copyright.gov and fill out the SR form. (
here's the form link:http://www.copyright.gov/register/sound.html)
Now to save money, you can put all your beats on 1 CD and submit it as one production or an album. Then you can list each track on that CD. Otherwise, you will spend about $30-$40 per song and that can add up.
Now, if you need to copyright something ASAP, go to the post office and say you want to "poor man copyright" your production. You will need to fill out a registered mail form and
mail it back to yourself. NOW NEVER OPEN THE PACKAGE! If it does come down to court, the judge will open the package with your production, the date will be on your CD and the package. That holds up in court that you produced that production on the package date.
Now, that's not 100% copyright! You still need to do it with the Government. But, to copyright a production takes about 3 months or so.