Graet post, I wanted to add two things :

- ssl modules must be loaded in the httpd.conf. This is generally performed by adding :

LoadModule ssl_module         libexec/apache/libssl.so
AddModule mod_ssl.c

- The VirtualHost directive can be used in case multiple websites are served by the same Apache instance for a fine-grained SSL configuration.

I also came across a similar article that discusses these topics :

http://www.codealias.info/technotes/howto_add_ssl_support_to_apache_web_server