Starting with LaTeX/PdfTeX, a small template

\documentclass[a4paper,12pt]{article}
 
% let's use some nice packages
\usepackage{times}
\usepackage{amssymb}
\usepackage{amsmath}
% set all margins to 2.5 cm
\usepackage[margin=2.5cm]{geometry}
% for fancy and easy modification of header and footer
\usepackage{fancyhdr}
% include hyperlinks in pdf file
\usepackage{hyperref}
% decide if run PdfTeX or LaTeX
\ifx\pdfoutput\undefined
% we are running LaTeX, not pdflatex
\usepackage{graphicx}
\else
% we are running pdflatex, so convert .eps files to .pdf
\usepackage[pdftex]{graphicx}
\usepackage{epstopdf}
\fi
 
% also include colors
\usepackage{color}
% define bottom line of paper, for DRAFT option
\usepackage{prelim2e}\usepackage[none,bottom]{draftcopy}
\draftcopyName{preprint / }{1.2}
\renewcommand{\PrelimWords}{Draft%
 -- contact: user@mail.yoursite.com -- www.yoursite.com}
 
% define a path for your images
\graphicspath{{.},{../images/},,{../../images/}{../../anotherdir/}}
 
% define a new command
\newcommand{\mylab}[1]{\label{#1}}
 
\title{Your Title}
\author{Your Name}
\date{\today}
 
\begin{document}
% show the title, author and date
\maketitle
 
% article's abstract
\begin{abstract}
body of abstract
\end{abstract}
 
\section{Section Name}
\subsection{Subsection Name}
 
% include the bibliography but using bibtex
\bibliographystyle{plain}
\bibliography{bibfile1,bibfile2,bibfile3}
 
\end{document}