use the geometry package to set margins: \usepackage[left=1in,top=1in,right=1in,bottom=1in]{geometry} http://bit.ly/bd4gT
use pdffonts to check whether fonts are embedded in pdfs http://bit.ly/T0DCr (another tip via @ssuri)
if margins are rendering incorrectly with latex->dvips->ps2pdf, try dvips -t letter http://bit.ly/15kuY4
to include a table of contents, use the pdftex package: \usepackage[pdftex, bookmarks=true]{hyperref}
use \pdfpagewidth and \textwidth (same for height) to scale the size of a document
make sure to always put figure labels *after* captions, as references will otherwise be incorrect
to typeset piecewise functions that are aligned, use the cases environment in the amsmath package
to include eps figures in a pdftex or pdflatex document, use \usepackage[pdftex]{graphicx} \ \usepackage{epstopdf}
to span a figure over columns in twocolumn mode, use \begin{figure*} … \end{figure*}
