For good general pointers on how to use interrupts, see IFI's white paper titled Using Polled or Interrupt-driven Timers at:
http://www.innovationfirst.com/first...ite_papers.htm
It does not specifically address using the external interrupt pins (labeled INTERRUPTS on your EDU RC), but the principles for using external or internal (i.e. timer) interrupts are the same.
For more information on configuring your INTERRUPTS pins for use with interrupt-driven code, read the Microchip PIC18FXX20 Data Sheet. General interrupt information is on pages 87-102. Note that by checking ifi_aliases.h you can find out the mapping of the microcontroller pins (RB2-RB7) to the INTERRUPTS pins. Specific information on these pins and their interrupts is on pages 106-108 of the data sheet.
As a final note, remember that all interrupts that you use MUST be low priority. If you try to make any interrupts high priority then you will see the PROGRAM STATE LED blinking red.