Hey Annie, welcome to the wonderful world of Arduino! 
There are alot people using the Arduino and other MCU's to build robots at http://letsmakerobots.com, alot of people upload their code too to give you some examples.
Take a look at this one in particular, I think it was posted on Arduino a while back but couldn't find the link:
http://letsmakerobots.com/node/2164
Happy building! Can't wait to see it rockin.