Use the columns environment to divide the slide into two columns. Then use \includegraphics to insert your image:
\documentclass{beamer}
\usetheme{Hannover}
\begin{document}
\begin{frame}
\frametitle{A frame}
\begin{columns}[T]
\begin{column}{.5\textwidth}
\begin{block}{Your textblock}
% Your text here
\end{block}
\end{column}
\begin{column}{.5\textwidth}
\begin{block}{Your image}
% Your image included here
\includegraphics[<options, e.g. width=\textwidth>]{<your image file>}
\end{block}
\end{column}
\end{columns}
\end{frame}
\end{document}