I'm gonna bet the shyness comes from a fear of rejection (of course correct me if I'm wrong). The simple solution is just be yourself, but be confident in yourself (girls love confidence). Also remember: she's probably nervous as well but has had to develop a thicker skin because of so many other guys that have approached her, like SD alluded to his post. Just know the right kind of girl wants you to be interested in her, not just for sex, so be a nice guy and not a jerk. If the chemistry is there for both of you, you'll be in a conversation in no time at all - and you'll soon be making your first date as well
Good luck.