Confidence? Yea right!
Right now, it sounds like you are suffering from a typical case of shamelessness. Right now, you don't want to approach women not because you have low confidence, it is because of two things.
#1. You are afraid to face failure and shame from failing.
#2. You are over-thinking it and thus losing your own comfort zone.
The best way to solve this is to just approach the women and shoot it. The more you do it, the more confident you will get. It doesn't matter if you fail, because there are billions more out there. Eventually, you will get to the point where you will be able to be confident and natural around strangers.
To answer your question on resources, check out Tyler Durden's "Real Social Dynamics". Awesome audio-lecture series designed to improve yourself and your game. I actually just covered the problem you are having right now, so I know you will find the answers you need in that.
"There is no better than adversity. Every defeat, every heartbreak, every loss, contains its own seed, its own lesson on how to improve your performance the next time." - Malcolm X