i have been hanging out with her for four years and I've finally worked up the courage to ask her out today. we are going to a movie and I figure I'll ask her when I drop her off at home. please give me some good tips.
You invested 4 years into a friendship. Are you willing to throw it all away? If she doesn't like you, the friendship (as it is now) is over. If you two hook up but it doesn't work out, the friendship is over. At best, you might gain a girlfriend, but is it worth the loss of a long-time friend? You might have a different type of relationship that is also desirable, but the friendship will be over. Sex will change things, if it even gets that far. Anyways, just give it some serious thought.
I am going through the same situation granted I haven't been friends with the girl as long. In my case I decided to tell her I liked her and tried to just be honest about how I felt. It has blown up in my face. Yet I would do it again, I would rather take a chance and fail the be a coward. Also in regards to what easyec says, I would say that yes there is a lot to lose but there is so much more to gain than just a girlfriend.