[Skunkworks] System Administrator - Advice

Seeing the good response James got on his "CCNA - Advice" thread, I thought it would be an opportune time to ask this. Say I'm working towards being a System Admin, What is the right place to start? What skill set do I need to have? What I'm I required to do in terms of professional courses, private study etc? Are these possessional courses over-rated, is there such a thing as the self taught System Admin? Regards, //James