Hello Singing and Vocal forums -

I have a very weak voice and would like to train my voice to be serviceable enough to make demos to send out to actual vocalists, so I am looking for some training materials. I have found a good bit of information on youtube but would like some podcasts I can throw on my ipod and work on in the daily commute. Has anyone had any success with any podcasts or know of any podcasts to recommend?

Any input is greatly appreciated.