Friend wants to have sex, but doesn't know anything about it

My best friend want to have sex but know nothing about it. I have talked to her about something and half of the stuff she doesn't even know what it means. She is only 15 and she said that she really want to loose her virginity like now. I am the same age but I am going to wait until I am out of school incase something happens, (I've watched 'Love,Rosie' ok). I am not a know it all about sex because I have never been there. So what are something I should know about or make sure she I familiar with??