hyperref, written by Sebastian Rahtz, maintained by Heiko Oberdiek, adds automatic hypertex links to LaTeX documents that are intended to become HTML (using latex2html or tex4ht) or PDF files (usign pdflatex). The example follows:
\usepackage[pdftex,
pdftitle={Test with LaTeX},
pdfauthor={DU Run},
pdfsubject={Test PDF output from LaTex},
pdfkeywords={test, LaTeX},
bookmarks,bookmarksopen,
colorlinks,linkcolor=blue,citecolor=blue,
urlcolor=red,
]
{hyperref}
add the codes similar to above to the preamble part of a LaTeX. Then run pdflatex, we'll get a PDF file with hyperlink, bookmarks.