Epigraphs are those neat quotations that authors put at the start of chapters (or even at the end of chapters: Knuth puts things at the ends of chapters of the TeXbook).
Typesetting them is a bit of a fiddle, but not impossible to do for yourself. However, the epigraph package will do the job for you, even in situations where it's particularly nasty to get right.
The package defines an \epigraph command, for creating a single
epigraph (as at the top of a chapter):
\chapter{The Social Life of Rabbits}
\epigraph{Oh! My ears and whiskers!}%
{Lewis Carroll}
and an epigraphs environment, for entering more than one epigraph
consecutively, in a sort of list introduced by \qitem commands:
\begin{epigraphs}
\qitem{What I tell you three times is true}%
{Lewis Carroll}
\qitem{Oh listen do, I'm telling you!}%
{A.A. Milne}
\end{epigraphs}
The \epigraphhead command enables you to place your epigraph
above a chapter header:
\setlength{\unitlength}{1pt}
...
\chapter{The Social Life of Rabbits}
\epigraphhead[<distance>]{%
\epigraph{Oh! My ears and whiskers!}%
{Lewis Carroll}%
}
The <distance> says how far above the chapter heading the
epigraph is to go; it's expressed in terms of the \unitlength
that's used in the picture environment; the package's
author recommends 70pt.
The package also offers various tricks for adjusting the layout of
chapter header (necessary if you've found a hugely long quotation for
an \epigraphhead), for patching the bibliography, for patching
\part pages, and so on. (Some of these suggested patches lead you
through writing your own package...)
The memoir class offers all the facilities of the
epigraph package. The Koma-script classes have
commands \setchapterpreamble and \dictum to provide these
facilities.
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=epigraph