Improve READMEs

nginx/sites-available/README.md

@@ -1,4 +1,11 @@
 Sites Available
 ---------------
 
-Define host definitions here
+Define host definitions here.
+It'd be a good thing if you keep your hosts indexed by domain name, eg:
+
+```example.com (handles traffic from both www.example.com and exapmple.com)
+foobar.com (as above)
+test.foobar.com (handles traffix from both www.test.foorbar.com and test.foobar.com)
+```
+

nginx/sites-enabled/README.md

@@ -3,3 +3,10 @@ Sites Enabled
 
 Symlink to `../sites-available/` for any site you want to enable. Conversely, remove the symlink
 in this folder to disable a site without permanently deleting the site's configuration.
+
+E.g. (we suppose your nginx configuration files are stored in `/etc/nginx`)
+```sh
+    $ pwd
+      --> /etc/nginx
+    # ln -s /etc/nginx/sites-available/example.com sites-enabled/example.com
+```