In the example below I'm showing how you can change a bunch of LaTeX document length parameters. The values don't really make any sense -- I've just thrown some numbers in there. I just want to remember how to do this for the next time I need to create a LaTeX PDF document.
(For what I'm trying to achieve today my goal was to get rid of all the margins on the left side of the page. Then I decided to throw in a few other values.)
I found some of these LaTeX examples on pp. 84-89 of The LaTeX Companion.