Hey do you have any resources like books or youtube that can help someone work on their voice?

Im not looking to get into voice acting at the moment, but I do love what some actors are capable of doing with their voice. For example James Gandolfini, his voice is completely different as Tony Soprano from his real life voice. Granted, he has voice and dialect coaches, but ANY book or video that can help me even begin to learn how to manipulate, open up, free my voice etc would be helpful, thanks! And, good luck with your new career.