Not too spam or direct anyone away from TR but Linux.com has a good "new too linux" section of articles linked off it's front page; should be top left or right.
If your interested in trying your own linux base OS install consider looking at Mandriva One or any of the other liveCD distributions. You can run them without touching your installed hard drive and have a good look at a prebuild setup. I'm partial to Mandriva due to the draketools. (You'll hear a great deal about "Linux" being only the kernel and Linux based Distros or OS all being different but similar; I'm usually one of the ones spouting that off admittedly.)
As for Grep meaning "too understand" it's an old Unix hackers term unless it goes further back even. (My bad, "Grock" means "too understand as does "Hack"; eg - I hack what your getting at. I grock what your getting at.")
http://www.catb.org/jargon/html/G/grep.html
"Globally search for the Regular Expression and Print the lines containing matches to it"
The Jargon file is a fun read and clarifies a lot in general if your interested. Also, ESR's essays around the Cathedral and the Bazzar (catb) plus FOSS in general are a worth while read as are Richard Stallman's essays though most of us fall somewhere between the two.
The first recommendation "new to Linux" collection is probably your best place to start though. There is also an article in there archives on a basic introduction to many cli commands if it's not also in the new user section.
Asking in the forums around here is also pretty good for getting a response.