I just recently discovered LyX in the repositories of my Ubuntu install (although its available for MacOSX and Windows as well), and let me say something briefly:
If you are a student, writer, publisher, or what have you, you should *definitely* be using it. Its so much easier to do type-setting its not even funny.
It took me about 2 hours to go through the included tutorial, after-words, I took an 8 page document I had been writing in a text-editor (not a word processor, think notepad) and within 15 minutes I had it sectioned, sub-sectioned, table of contents, bibliography, etc. All consistently typeset. In fact things like sectioning and cross referencing are handled automagically for you.
For example:
If you create say…
Section 1: Farms
Section 1.1: Cows
Section 1.2: Chickens
Section 1.3: Horses
Section 2: Crops
….etc.
And then decide you want to make it look more like this:
FARMS
Section 1: Livestock
Section 1.1: Cows
Section 1.1.2: Milk or Meat?
Section 1.2: Chickens
Section 1.3: Horses
Section 2: Crops
…etc.
You do not have to go back and re-indent, nor do you have to renumber all your sections, LyX handles this automagically for you. Also if you put in cross referencing material like (See Section 1, chapter 1,) And then decided to move Section 1 to be section 2, your cross references would change automagically as well =).
Seriously, this will save you so much time its not funny.
To install LyX on Ubuntu simply type in terminal:
sudo aptitude install lyx
Same thing should apply to most other debian based distros (That use the 2.6 kernel) check your repository if you use yum or rpm, for MacOSX and Windows install, check the LyX website (use google ya lazy bum)