NGINX server configurations.

1) To find path of nginx.conf file.
locate nginx.conf
It will give you locaiton of nginx file.
/usr/local/nginx/conf/nginx.conf                                                                                       
/usr/local/nginx/conf/nginx.conf.default

2)To set domain name
Edit nginx.conf.default
nano /usr/local/nginx/conf/nginx.conf.default
Change server_name settings

server {
                listen       80;
                server_name  localhost; #instead of localhost set live domain name like abc.com

                access_log  logs/localhost.access.log  main;

                location / {
                    root   html;
                    index  index.html index.htm;
                }
        }
}

3)After making of any changes in nginx.conf file you need to reload it.
/etc/init.d/nginx reload

4)After making any changes of project files on server you need to restart nginx server.
/etc/init.d/nginx restart

5)To kill process of nginx
ps aux | egrep '(PID|nginx)'
and kill the PID

Refer site:http://library.linode.com/web-servers/nginx/configuration/basic