How to think like a Linux Administrator.

• Everything is a file.*
• Yes even that.
• That too.
• If you're going to do it more than a handful of times, script it.
• DOCUMENT your scripts so when you go back later, you'll be able to understand them.
• There are four commands you really need to become familiar with, probably in the following order.
• grep
• vi
• awk
• sed
• Yes vi.  Every system you'll ever run into will have some variant of it.  That's can't be said for pico / emacs / gedit.
• Learn how to edit files using 'cat' in case vi isn't there.
• Learn one of the basic shells (bash / ksh / csh).  I used to mention sh, but bash has supplanted it nearly everywhere.  Learn it until you can't use other shells anymore.  Then learn the other ones.
• No they're not the same.
• Tweak out your PS1.
• Have a bunch of widgets on your desktop.
• Use the /dev filesystem.
• Learn regular expressions.
• Never refer to it as regular expressions again.

* Okay, its not really a file, but you can probably treat it like a file, or at the very least, a stream of characters.