Prepare arduino to listen to serial commands, standard Arduino IDE would accept character that you can map to functions to move it to different directions.
Write a python program that sends serial commands via usb port. Save this and run it on your Raspberry.
Build interfaces such as Web page with Javascript and NodeJS to add buttons so you can control it remotely.
Refer to full tutorial on how to program and control your rover via wifi and web browser at http://www.linuxcircle.com
