Arduino Nano v3.0 and external battery

I want to connect a 9v battery in my Arduino Nano (with a button (switch)*), how do I do this and what resistors to use?

Use in the project: Arduino Nano v3.0; Piezo; 2 LEDs with 2 Resistors; Ultrasonic Sensor. Button.

* http://img.bhs4.com/36/8/3681901245dc494588038b4e1c6537f890f017b9_large.jpg

Thanks. :grin:

To switch voltage from the 9 volt battery to the nano, hook the switch in series with the +voltage and the pin on the nano you want the 9 volts to go to ( I guess that would be Vin). Is that a push button (only closed while you hold it)?

on / off button, is pressed alone