check cipher before daemon start

fix #280

README.md

@@ -28,12 +28,19 @@ See [Install Server on Windows]
 
 ### Usage
 
-    ssserver -p 8000 -k password -m rc4-md5
+    ssserver -p 443 -k password -m rc4-md5
 
 To run in the background:
 
-    ssserver -p 8000 -k password -m rc4-md5 -d start
-    ssserver -p 8000 -k password -m rc4-md5 -d stop
+    sudo ssserver -p 443 -k password -m rc4-md5 --user nobody -d start
+
+To stop:
+
+    sudo ssserver -d stop
+
+To check the log:
+
+    sudo less /var/log/shadowsocks.log
 
 Check all the options via `-h`. You can also use a [Configuration] file
 instead.