Purchase appropriate instructional books. Popular books include 'Harmony Singing By Ear," by Susan Anders and "How to Sing," by Graham Hewitt. These books can be purchased through www.amazon.com. Many libraries have various instructional books that you can check out free of charge as well.
Purchase instructional videos or CDs to guide you through exercises. Popular titles include "Voice Lessons To Go Volume 1: Vocalize and Breath," by Ariella Vaccarino and "Learn To Sing Like A Star," by Ava Landman. These instructional guides are particularly helpful if you learn best through seeing and hearing others demonstrate proper techniques and exercises.
Hire a voice teacher if your goal is to become a professional singer. While it is possible to become a great singer on your own, using a trained teacher is the fastest way to see an improvement in your voice and learn vocal music.
Practice your scales at the piano. While it may seem like a tedious task, it is an essential part of learning vocal music. Practice with other singers to work on harmonies. Try to practice your scales for at least 20 minutes per day.