If you truly want to perfect your singing voice, I recommend a book by Jeffrey Allen.
http://search.barnesandnoble.com/Sec...ret+of+singing
I am a front man in a band and also have been doing a solo project where I record and play all the instruments myself. I reached a point in solo music where I didn't have a singer, because people kept flaking out, so I said, "**** it" and decided to do that myself as well.
Not going to lie.... I sucked ass at first. The voice is an instrument like any. It has to be strengthened and perfected. That book helps you understand how the whole diaphragm works, and shows you exercises to strengthen it. I was amazed at my progression from the exercises, but you have to be dedicated to it. It's just like a work out. Has to become a routine.