Some words of wisdom from Peter Hancock
I liked Dave Clarke's tips and Matt Might's diagrammatic explanation of what a PhD is all about. Alan Bundy's guide to how to do research is great too. Tara Brabazon gives valuable advice on choosing a supervisor.
Applies to PhDs? "Write without pay until somebody offers pay; if nobody offers within three years, sawing wood is what you were intended for." —Mark Twain
"You know you've grown up when you think that your Ph.D. thesis isn't that bad after all." —Max Cresswell (found over there)