Arduino Routed Network via XBee2

Good Day,

I am planning to experiment with Arduino and XBee2. Sending data to and from my Arduino controllers through the use of XBee2 modems. What I do not cleary understand is how to tell my XBee2 device attached to my Arduino Uno via an XBee Wireless Shield to encapsulate(packetize) any data that I want to send through it. Wether it is transmission over RF or receiving over RF.

If any one can supply links or info with regards to this matter, I would appreciate it.

Like, where can I download the XBee2 library for Arduino Uno?

Thanks