Headfirst into an empty pool...

[headsplice]

First, a little background:
Three weeks ago today, I got a new job. One day, I'm doing proprietary hardware/software tech support for a trucking logistics firm, the next I am a network admin for a media duplication facility. Wheeee! One problem: it's a mixed Linux/NT environment. The NT part I have covered (I have enough experience to be able to click through menus and find out what I need to find out). Linux, however, is a little bit more difficult hurdle to overcome.
Now, the question:
What would the Linux folks recommend out there for a crash course (and I mean CRASH, I have to build a business system server in the next couple of weeks) for getting myself going as a Linux admin? I will have a couple of other folks that will be helping me get the server set up, but after that the machine really is my responsibility.
thanks for any help you can give.

cheers!