Ask HN: How to setup a secure server on Amazon EC2

I have been looking at scalable web hosting solutions and I am interested in starting a web server on Amazon's EC2. It is simply because I can run many of my processes in the background and reduce the amount of online processing.

I have no experience in setting up and checking for security holes in my Apache server. I am wondering what is the best practice for setting up a secure webserver on Amazon machines?

Is there any AMI that is already configured to serve as a secure web host?

Thanks

Siah