Here is a great discussion about voice. I found it very helpful and hope you do as well. Jan Field's KidMagWriters.com is always full of great information. Check it out at http://www.kidmagwriters.com/index.htm.
Finding Your Fiction Voice
By Bonita Pate Davis
Finding the right voice for your magazine short story could mean the difference between a finished story that really works and one that doesn’t—quite. Take a story, any story, and write it twice. Use the same themes, characters, and plots. But employ different voices. One works; the other doesn’t.
For an in depth review as well as wonderfully concrete examples, please see Bonita's article at http://www.kidmagwriters.com/index.htm.