Here’s an excellent, short and to-the-point guide on getting FastCGI configured for Lighttpd:

http://www.cyberciti.biz/tips/lighttpd-php-fastcgi-configuration.html

Of course, this is assuming PHP, MySQL (if required) and Lighttpd are already installed:

  apt-get install php5-cli php5-cgi lighttpd mysql-server

I also needed to reconfigure MySQL for a low memory machine (112MB). I did that by doing the following:

Replace /etc/mysql/my.cnf with the my-small.cnf found at /usr/share/doc/mysql-server-5.0/examples/

  cp /usr/share/doc/mysql-server-5.0/examples/my-small.cnf /etc/mysql/my.cnf

Edit your new my.cnf and do the following:

Uncomment skip-bdb
Add a new line beneath it for skip-innodb

Finally, restart your mysql server:

  sh/etc/init.d/mysql restart