The WordPress has been installed into
/var/www/wordpress-mu

You should point this to the DocumentRoot of your web-server:
   # ln -s ../wordpress-mu /var/www/htdocs/wordpress-mu
(make sure you use a relative symlink since Apache is chrooted)

and proceed to complete the installation by reading:
/var/www/wordpress-mu/README.txt

You can ensure you have a working install by accessing:
http://<localhost>/wordpress-mu/
