Letters to a young graduate student: Part I

Every so often when a new batch of graduate students join our department, I often get tasked with telling them, in ten minutes or less, Everything You Wanted To Know About Doing a PhD Here (But Were Afraid To Ask). I'm not sure if they ask me to do this is because I'm a "mature" student, or friendly, or a woman, but in any case I don't mind. I also keep finding myself somehow giving impromptu lectures to whole groups of students on How To Do Research....