I want to be a singer...how can I get started?

I love to sing...and I'll admit that I have a really good voice. I practice every day in my room and I know I'm getting better. My mom says I have a beautiful voice and encourages me to sing. But I'm SOOO shy! And I can't play any instruments at the moment. Is there any way I can purchase or possibly rent the music---only the music---from some songs like the ones from the Fergie CD the Dutchess? Thanks to all who give me valuable answers. I also want to act. How can I get started on that?