The fastest and cheapest way to have your songs copyrighted is to write them and put it in some tangible, fixed medium. Like posting a song here and/or at soundclick. That is all there is to it. Now if you are talking about "registering" your copyright, there is only one way in the U.S. to do that (one, uno, not dos, un, bat, satu ...) -- file your copyright with the Library of Congress (LOC).

If you (or the same folks) are the only copyright holders on various songs, then you can do a collection real cheap at the LOC.

Kevin

Now at bandcamp: Crows Say Vee-Eh @ bandcamp or soundcloud: Kevin @ soundcloud