Clown,
Congratulations! You've taken the first step in ridding yourself of Microsoft Word. I won't bother going into why I think that MS Word is a terrible program, but I will say that LaTeX is what I use for creating documents of any size.
Before starting down the rabbit hole, I should warn you that if you want something not unlike MS Office, Open Office is a reasonable approximation, and further that Microsoft even sells a version of Office designed for the Mac. If all you want is to find a replacement for Microsoft Office on your Mac, then either of these options will be sufficient. If, however, you are looking for a very powerful way to create very complex documents, which incorporates some very useful features, then I consider spending time learning to use LaTeX a worthwhile investment.
First things first. You likely won't be proficient in LaTeX after using it for a day, even if you're accustomed to learning intricate software quickly. That is because LaTeX is not the same sort of application as MS Word. They don't just have different creature types; LaTeX is a land, and not a creature at all. More specifically, MSWord is a What You See is What You Get word processor. You arrange and manipulate the text on the screen so that it looks just how you want. The text and the formatting are merged together in a single document, inseparable from one another.
LaTeX is something else entirely. To create a LaTeX document -- often a PDF file -- you first write simple, plain text. The plain text contains tags and signifiers to indicate how the text should be laid out; think HTML but far more powerful and more precise. Then, you run the plain text through a process which produces as its output a document. I don't know if you program, but if you do, you can think of LaTeX as compiling the text, producing a document instead of a program. Put another way, you create a blueprint, and then LaTeX creates the house.
Now, I know what you're thinking. That sure seems like a lot of work, and I can't even see what I'm working on until I run it through an arcane compilation process! I'll agree that LaTeX is not as intuitive to use as MS Word, and it can have something of a learning curve. That said, it also has several salient advantages. First, by separating the text writing from the text formatting, you are able to separate what ought to be two different tasks from each other. To me, it is very clean to keep these two apart. Further, LaTeX does the formatting for you. You set parameters, or even use packages that other people have made. Then you type, and LaTeX takes care of making your document fit whatever guidelines you set for it. Want four inch margins, not the two inch ones you'd been using before? In MSWord, you need to go through the whole document and drag the margins around whenever you want to change this. In LaTeX, you simple change a variable and typeset the document again.
Those are just the tip of the iceberg. There are far more comprehensive and well-argued accounts on the internet of why LaTeX is a superior document creation tool than MSWord. There's a reason that so many people in computer science research use it, myself included. It will be frustrating and perhaps a bit perplexing at first, but it isn't as complicated as playing Magic. There are also plenty of great, free tutorials online for learning it. I just typed "latex tutorial" into Google, and it had several tutorials which I skimmed, and they looked fine.
As for using LaTeX. While you can use any text editor and a terminal, there are some good GUI interfaces to facilitate the process. I use TeXShop myself and have been very happy with it. It's free and open source, just like LaTeX.
http://www.uoregon.edu/~koch/texshop/I wish you the best of luck, and hope that you discover a very powerful application.
Rich
