Ask her out to do something one night. I would stay away from asking her to lunch or coffee, because then she might immediately label you as a potential friend...that would be bad if you want more.
If she gives you an excuse that she can't, but offers another night or something, that's cool. If she just gives excuses, don't try too much just accept she's prob not interested.
Oh and I probably wouldnt' ask her out to the movies seeing as how she works in a video store hehe =)
EDIT: Just ask her out straight, don't try to find a clever way to do it or you'll end up sounding like a fool
