To protect original songs you can register them with the US government for $20. Click here: Copyright Office for details. Look out for scams that offer to do the same thing for more money.

I don't think the process can ever be made painless but avoid any deal where you pay to have your song published. One place to start is the book "The Songwriter's Market" published annually. It lists publishing and recording companies and what kind of songs they are looking for. I would also be interested in hearing others' experiences selling songs.