Ask Slashdot: What Training is Necessary in Becoming a Sysadmin?

Keith Bassett submitted a question which might interest a few of you out there who aren't in the industry, but might be looking to get into it. He asks: I am currently working in IT as an installer/support person for Pick based systems, and for Win32 networks. This is fine, but I really want to be working as a Unix/Linux administrator. My trouble is simple. What sort of training have the administrators who read this page had? What sort would you recommend? I am willing to hear any and all opinions on this, and could seriously use the input." Keith adds the following.

"Please don't just send me mail telling me to learn Linux... I already have a small network with three machines running it at home. I need advice on how to make it my career."