[plug] What is most important?

[Jay Warwick]

As a newbie I want to implement various types of systems (mail,
anti-virus, web servers, etc) for myself and others - including
business.

I currently use Linux mainly from the GUI, but if I wanted to learn the
most about Linux administration in the shortest amount of time (say 3
months) what should I concentrate on the most to ensure I have a really
good base to build upon.

Thanks

JW