Hi Tammy
"The Science Of Self Confidence" by Brian Tracey is fantastic, Instant Confidence" is good as well by Paul Mckenna, it comes with the self hypnosis cd which I think works really well. Those are the two which spring to mind. Check out the audio books section for those books and others too. if you are looking for more general material I would recommend Tony Robbins, Bob Proctor and Jim Rohn as all being very good for general overall personal development.