How to connect to my Arduino Board

Hello everyone , I hope I will be clear and sorry by advance for my bad english .
So , first I will tellyou a little story : 4 guys have to make a project , which is to make a robot that can be controlled by a smartphone ( android ) . The robot will be connected via Wifi and we have to be able to control it from anywhere ( of course we need internet ) .
My problem is : I don't know where to begin , I found a part of code that allow me to connect my arduino board to my box but i don't know how to receive information from android .
If somebody could help me a little bit , It would be cool .
Thanks you a lot .
Freddykong.

A very simple web controlled bot project.

http://www.lynxmotion.net/viewtopic.php?f=20&t=6343