How to make a robot


I’d like to make a robot for a school science project. My robot has to move using wheels. I have to do an experiment on the robot. I chose to run tests on how different wheels affect the robot on different surfaces. These surfaces are mud, sand, and asphalt.

Can anybody tell me how can I make a fully autonomous robot with interchangeable wheels, a programmer, a micro controller, and all the other things that will make it fully autonomous.

Please tell me or send me web addresses where I can find the information.

You have 2 limits:
The robot has to be under $150 and it has to be done by the end of January and the start of February 2012 at the latest.

I already have 2 NiMh 7.2 Volt, 650 mAh batteries.

I appreciate any help or suggestions you can offer me. Your help will be greatly appreciated.
Thank You.

FYI to everyone.

If you go on the Category Electronics, you will find a post named What programmer should I buy or make. If you have anything to say, please post it on 1 of the posts.

Thank you,

visit on mhobbies and get useful information about how to make a robot.