How long does it take to become a Linux Administrator?

How long does it take to become a Linux Administrator?

It depends on what you know and how good you are at solving issues.

For some useful reading:
http://tldp.org/LDP/sag/
http://www.faqs.org/docs/linux_network/
http://www.linuxsecurity.com/docs/SecurityAdminGuide/SecurityAdminGuide.html
http://www.linuxsecurity.com

You may also want to look at getting certification. There are still many organizations that think they mean something and in some respects they do, but certs need to be backed up with real knowledge and experience. I'm not really big on getting certs for various reasons, but I have Brainbench certs. They still offer some of them for free and I think they are accurate. For more on my thoughts of Brainbench certs see the bottom of my resume page here: http://www.t3technet.com/resume.php