it's a pretty sophisticated setup. Many big companies like facebook/google etc are using techniques like this ( memcache / apc / varnish ). This is not a full explained setup that goes into every detail its rather a 30 minute tuttorial you can follow and end up with a decent base configuration.

I already created another tutorial showing a webserver configuration with apache2/ispconfig/mysql this might be easier to follow if you are not that good with administrating webservers. ( http://blog.internetz.me/index.php/2...perfect-setup/ )