3 Answers

If there is a Chapter of the "Barbershop Harmony Society," in your area, go there, they will teach you to sing in your voice range and to sing well.

The "BHS" is in countries all around world. You can find one near you at

http://www.barbershop.org/

A good singing instructor/tutor/voice coach. 

Signing up for a few singing classes or joining a choir can teach you vital skills about posture and breathing that can transform your singing. Make sure you're breathing "with your stomach" instead of in your chest. Warm up before serious singing by doing scales and vocal exercises (you can find some on youtube). Practice often and push yourself outside your singing comfort zone. Don't be afraid if you can't hit the notes, just try your best and you'll get there with practice! Good luck!