Record your single. It sounds simple, but this will be the most important part of the process. You have to do everything in your power to ensure that you have recorded the best possible representation of not only your song, but of you as an artist. If your single is good, word of mouth will be the best marketing tool you have.
Play live gigs and sell your music there. If you have not developed a following yet, you will have to start small and for less money, but if you go out and rock the house every time you play, people will take notice and you will start getting better-paying jobs. Regardless of whether you are playing a dive bar or an arena, make sure to set up an area where you can sell your CD single. Recruit friends and family to handle the transactions while you’re on stage.
Sell your CD on the Internet. There are limitless possibilities, not only on sites like Amazon and eBay, but also through sites that specialize in selling music. There are sites that sell all genres and also sites that specialize in individual genres as well. Do some research to see which site best fits your purposes.
Create your own website and sell your CD online. If you do not have the computer expertise, you can hire someone or even go through friends and family. Chances are someone will be able to build a basic website for you. The most important part (other than the sales page) will be to include clips from your single, and possibly other works as well. No one is going to buy a CD single without first hearing what the artist has to offer.
Submit your music to record companies and talent agents. It is unlikely you will picked up just to sell a single, but, if you are good enough, they may sign you to a development deal and eventually release your single as a part of a full album.