A flow chart is a tool commonly used by programmers to illustrate and determine the logic their program will follow, before any real code is written.
Flowcharting Basics
If you decide to use a flowchart, (you should always plan your code, whether it be with a flowchart or some other clever tool) you can make the process easier and use office software to help you create it.
I use Microsoft Visio.
If you are just starting to learn C, and working primarily with the robot, I suggest taking a look at
these presentations, along with the programming forums here on Chief Delphi.