How to get title of a citation?

biblatex package provides \citetitle command for this. You'd better read the manual and examples of this huge package.

A simple example:

\documentclass{article}
\begin{filecontents*}{foo.bib}
@Book{Knuth:ct-a,
  author =       "Donald E. Knuth",
  title =        "The {\TeX}book",
  publisher =    "Addison-Wesley",
  year =         "1986",
  volume =       "A",
  series =       "Computers and Typesetting",
  pages =        "ix + 483",
}
\end{filecontents*}

\usepackage{biblatex}
\bibliography{foo}
\begin{document}

\citetitle{Knuth:ct-a}

\printbibliography
\end{document}

The \citetitle in biblatex prints also markup, if you just way the raw title printed use \citefield:

\citefield{my-referenc}{title}