Practice your singing daily. This is the most important step. Practicing and evolving your talent prepares you for international display. To be successful as an online singer, you must hone your talent religiously. See Resources for singing exercises.
Sign up for an account with YouTube or another video hosting site and upload weekly or daily videos of you singing. This will expose you to actual viewers who can offer feedback, criticism and encouragement. Not all criticism will be kind.
Record your first video for the site and make sure that you state your name clearly. This is important; it helps the viewers connect with you and remember you. Sing clearly; your first video will set the tone for all other videos. If you sing poorly in your first video, many will not stay on to watch the second. Do as many takes as you need to to get the right video for uploading.
Read your feedback and comments and apply them to your rehearsals. Often a singer's biggest mistake is not listening to her listeners. Thoughtful insight can let a singer know if she is too loud, too pitchy or not in key. Expert singers and managers often have accounts on YouTube and offer advice on videos. Let the unhelpful feedback roll off your shoulders; it won't help to dwell on it.
Enter contests on YouTube and other video-hosting sites. These are the quickest ways to gain maximum exposure and begin winning and earning money. YouTube has dozens of contests every month. Professional managers use these contests to scope out talent. With practice and determination, you can get discovered online and become a singer.