"Two of the most famous products of Berkeley are LSD and Unix. I don't think that this is a coincidence."
(Anonymous quote from The UNIX-HATERS Handbook.)
Unix has acquired quite a reputation for consuming novice users (and occasional system administrators) whole with it's hostile behavior and obscure command syntax. The reputation is not entirely undeserved. Unix came from something called MULTICS via a video game. (No, I didn't make that up.) So basically you're using Unix, you're working with the rubble leftover from a good game of space asteroids or some such.
Add to this the fact the Unix is sort of an underprivileged operating system. It was written and developed by programmers. (That in and of itself should explain alot about it's eccentricities.) Their intent was not to create the next up and coming operating system. So rather than build a house they made a zillion little blocks that they could use later to construct a house in dozen different architectural styles. So rather than getting a house where you can walk in, prop your feet up and watch TV you get a pile of blocks with letters on them, representing commands that could maybe, possibly look something like a house. What's even more fun is that the letters you type in to run the commands have nothing to do with what the commands do. Whee!
This does allow you to do some funny things from the command line. At your prompt try typing make love. Tee, hee. When I began working with Unix the only other operating system I had any experience with was Mac. The operating system on a Mac is so well disguised that you don't even know it's there really. I think this was an advantage as I had no expectations on how an operating system should behave. In other words I had no clue how bizarre Unix is. If I'd known I probably would've scared myself out of learning to use it.
So you have an unfinished, underprivileged pile of blocks that lots of people seem to want to play with. It's messy and unfriendly, but ooh, tack on a graphic interface and ta-dah! It looks much better. So now you have a messy, unfriendly, underprivileged and unfinished pile of blocks thinly disguised inside a snazzy box. (Pay no attention to the man behind the curtain...) Sometimes the whole thing reminds me of those bronze plated buffalo chips they used to sell out west.
Unix as acquired a reputation as something that can only be used by people who learned 14 programming languages by the age of ten and build all their home machines from scratch because it's fun. This is not true. If it did my artsy-fartsy background would have prevented me from ever touching the keyboard. There are two basic premises that would've saved me alot of angst in learning Unix. First, it does not make sense. Period. None. When you find something particularly nonsensical, if you go to someone who's been doing Unix for a long time and ask them about it they will look pained and say, " Well that's just how it is. Because it's RIGHT!" Better just to accept that it doesn't make sense. If you frighten the wizard too much they may not help you anymore and that's a bad thing. Second, should you at any time have a little nudge of intuition that says, "Hey it must work like this", run away from it like your hair is on fire! Not only is that not the way it works if you try it you'll probably cause extensive havoc. (Yes, I did learn that one from experience...)
Attaining some basic level of proficiency in Unix is not impossible. Particularly if you go about like you're learning an alien language from some planet that you've never heard of. It bears no relation to reality or to the rest of your life. It just is what it is. Now as long as you don't take a close look at a Sendmail configuration file there's nothing to be frightened of. (well, not much at any rate)
There are alot of good online tutorials for learning Unix. I've also found it invaluable to have books around that I can look things up in. I've actually read all the way through some of them. Yes, I know. I am embarrassed and I should. I read Unix books. My favorite for looking up commands is UNIX in Plain English. It's from MIS Press, written by Kevin Richardson and Eric F. Johnson. And it's under twenty bucks, which is extremely rare for a Unix book. There are always man pages, but, well they're man pages. I haven't found them to be real useful for finding out what commands actually do. I do use them for looking up command options and syntax.
Contrary to popular belief, not all computer books are written by people so humorless and dry that they are in danger of spontaneous combustion. I've found a few, the only ones I've read cover to cover, that are good for laughing out loud while learning something. My favorite is The Underground Guide to UNIX by John Montgomery, published by the Addison-Wesley Publishing Company. Right now that one will suck twenty-five plus tax out of your wallet, but it's worth it. UNIX for the Impatient is another good one for reference. It's not light reading. You may want an espresso or a big bottle of Jolt as a reading companion. It is well indexed. If you want to find out how to do something specific it's easy to look it up.
Also from the Addison-Wesley Publishing Company is Getting Started with UNIX and X. It's written by Torbjorn Andreasson and Jan Skansholm. This one is easier to sit down and read. You can probably do it with a cappuccino or a Mountain Dew. It's a good introduction to the way Unix and the X Window system work as well as how to use them.
When you reach the point where you're convinced you've made a serious vocational error and should consider sheep farming instead there's the UNIX-HATERS Handbook. It's from IDG Programmers Press, written by Simson Garfinkel, Daniel Weise and Steven Strassmann. A great deal of the contents come from the UNIX-HATERS mailing list that was started 1987 by someone who was mortified to find himself stuck with, well Unix. The book comes with a UNIX Barf Bag, cartoons and other things to make you laugh.
The best way to learn is by doing, so dive in! And don't worry about hitting your head on the bottom. It's plenty deep in here.