Chris from PyroElectro has posted this tutorial on interfacing with XBee.
Getting started with XBee can be tricky, even though it shouldn’t be. Here is a drop-dead simple guide to using XBee modules out of the box. The tutorial shows you how to build a wireless interface with XBee modules between two PIC 18LF4520 microcontrollers.
XBee wireless interface tutorial - [Link]