How to create two separate indices: Subject index and Index of Authors

you should maybe have a look at \usepackage{imakeidx}

\documentclass{article}  
\usepackage[english]{babel}  
\usepackage{imakeidx}
    \makeindex
    \makeindex[name=authors,title=Authors,columns=3]
\usepackage{natbib}  

\makeindex  
\begin{document}  
\citeindextrue   

This is a  text with few references, e.g. \cite{Doreian05} or \Citet{Doreian05}.\\
And it has fancy authors. \index[authors]{Doreian, Patrick} \index[authors]{Batagelj, Vladimir} \index[authors]{Ferligoj, Anu\v{s}ka}
key words: network\index{network}, blockmodeling\index{blockmodeling}, and so on.  
% bibliography  
\bibliographystyle{mcbride}   
% the file with bibliography entries blockmodeling.bib  
\bibliography{bibliography}
\printindex[authors]
\printindex  
\end{document}

hopefully it is helpful

Disclaimer: i've not tested this tex-code - just written down some ideas.

there's a good entry in the uk tex faq that shows several options. if you have tex live installed, you can access this via texdoc multind.

unfortunately, it doesn't include imakeidx (suggested by @epsilonhalbe), a package which looks quite promising; i've notified the faq maintainer of the omission.

UPDATE: the faq has been updated to recognize additional packages for preparing multiple indexes; well worth visiting if you need this facility.