[jee7s]

I'd suggest starting off with some available default code, so you can at least you can get the robot up and running.

As for customization...to properly use MPLAB, you need a combination of architecture and programming knowledge. The syntax is (essentially) ANSI C (not C++ or C#), and there are many books available on C programming. To really interface with the controller properly, you need to read up on the processor architecture (Microchip's PIC18F8722). This means deciphering things like this:

TMR0L (the low byte of timer 0)
TMR1IF (timer one is full/overflowed)

Thankfully, IFI's default code renames the ports to the names you see printed on the outside of the box. Also, Kevin Watson's FRC code handles a lot of the deciphering I mentioned above. Both are good starting places.

A big thing to keep in mind is that the PIC doesn't do floating point efficiently. This means that fractions/decimals/rationals slow the processor down. As an example:

i / 2
is more efficient than
0.5 * i

so, stick to integers as best you can.

In the end, programming the controller is a lot like algebra. But, C has its twists, so you need a good book on C to reference for syntax and errors.

-JEE