If you are using a shield, then you should be able to plug the XBees in and start sending data.
If you are not using a shield, then double-check the UART voltage of your Arduino. If it's 5V, then you will want to do some level shifting to avoid damaging the radio. XBees are 3.3V only, and applying 5V to any pin will damage it.
The Series 1 (802.15.4) is perfect for this project and should work out-of-the-box without any additional configuration.
On the Arduino, you're treating them as a simple serial connection. On the first, you'll send the data as a Serial.Write()
, on the other, you'll receive it as a Serial.Read()