You've already done the hard bit, and she must fancy you cos she said yes!
Have a careful think about where and when you're taking her. The aim of a first date is to have a good chat. So a bar on a Thursday-Sunday evening is a bad idea, you'll not get moved and you'll have to shout in each others' ears! A nice moody bar with soft lighting on Monday-Wednesday evenings is a good plan because it'll be quiet and relaxing.
Apart from that just ask lots of questions, and try to ask fruther questions based on her answers because it sounds like you've been listening.
Good luck!
