Fancy Page Headers

Fancy headers allow you to customize the header and footer line.

Document layout:

% ...
\usepackage{fancyhdr}
% ...
\begin{document}
% ...
\end{document}

Index page:

To find out how to force your index to use fancy headers see Indexes

Example for an article:

% ...
\usepackage{fancyhdr}
\pagestyle{fancy}
\renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}}
\fancyhf{}
\fancyhead[LE,RO]{\bfseries\thepage}
\fancyhead[LO]{\bfseries\rightmark}
\fancyhead[RE]{\bfseries\leftmark}
\renewcommand{\headrulewidth}{0.5pt}
\renewcommand{\footrulewidth}{0.5pt}
\addtolength{\headheight}{0.5pt}
\addtolength{\footskip}{0.5pt}
\cfoot{<author>}
% ...
\begin{document}
% ...
\end{document}

NOTE: Fancyhdr will use Margin lengths (as in Small Page Margins), therefore margins should be set before fancyhdr.