First off: thanks for the praise. I am sure most of the others would have told you the same, i was probably just the one typing the fastest. ;-)
A few (unsorted) extra points and clarifications:

- reading man pages
This is an extremely helpful skill, because man pages are a treasure trove of information, unfortunately written in a style that needs getting used to. I guarantee you that you will for the first three months wonder why everybody is emphasizing them. For the rest of your life, though, you will wonder how you could get so old without having had access to them. They are, essentially, a reference: you find everything there if you know what you search for. I consult them several dozens of times every day (there is absolutely no shame in knowing where to search) and you will do the same (like everybody else working on a UNIX system does).

- regular expressions
Basically they are specialised mini-languages to describe text patterns. Notice, that there are several flavors of them and you don't know all the differences but you should - from the beginning - be aware that there these flavors. Since they work the same in different tools (grep: BRE, awk: ERE, sed: BRE, egrep/"grep -e": ERE, ...) learning them makes you learn several essential tools at once. Have a look at the "Shell scripting" forum and you will notice that two out of three (if not even more) threads deal with the mentioned tools.

Finally, my personal book recommendations:

"sed & awk" by Dale Dougherty, published at O'Reilly
"Hand-On Korn Shell 93 Programming" by Barry Rosenberg (perhaps the funniest and wittiest computer book i ever had the pleasure to read)
"The AIX Survival Guide" by Andreas Siegert is a bit aged, but it still sits on my work desk daily if that means anything. I have three copies of it and every bit of spare space filled with annotations by me. Two copies are so worn down i bought a third one for daily use just to make them last longer.

I hope this helps.

bakunin