Personally, I don't. No one out there is trying to steal your songs.... heck it's nearly impossible to get folks to listen to them.

If you are going to release them on a commercial project, yes. You should copyright them. Plugging them to publishers, nope. The publisher is not going to steal your song if you're dealing with legit publishers and you should know who you're dealing with in that regard. They will copyright the song in their name if they are interested in representing your song to artists and other commercial projects. You simply have a writers contract with the publisher.

Hope that helps.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.