These instructions are also covered on the Nginx Wiki.
The prerequisite is that you have already installed Nginx and you are able to run PHP files via the FastCGI-wrapper from Nginx.
Now you need to set up a virtual host in Nginx with configuration settings that are similar to those shown below.
But enough of the disclaimer, on to the actual configuration — typically in
The above configuration sets up a virtual host `example.com` with rewrite rules suited for SilverStripe. The location block for framework php files passes all the php scripts to the FastCGI-wrapper via a TCP socket. Now you can proceed with the SilverStripe installation normally.