I've had a crush on her for 2 years and I finally want to do something about it?

I'm not great friends with any of her friends, I don't know how to start becoming their friends in order to get to know her a bit better without it being random sudden and strange, we chat on fb sometimes but I don't want to overdo it. Her best friends always around and I feel intimidated. I just want to know the best way to get to know her without coming across as a loony