First thing, don't rush, you'll be more nervous and might say something that makes you look silly.
Just hang out with her some time, be flirty but not over powering, just be confident and hang out and have fun, make sure she has a good time just hanging out with you. Maybe drop some hints here and there that you like her, and see if she gives off the same vibe, or drops hints herself. Of course you can always have your friends inadvertantly talk to her about you but not like "Will you date so and so" more along the lines of I heard you and "so and so" hung out the other day, he's my main squeeze, I hear he thinks your really cool, what do you think of him.
You know stuff along those lines, don't be overly cocky and just be nice be yourself and have fun!