Just when you go to the post office or where ever you are going to ship it from just ask them for tracking and they will give you one. Once you have that come back to this auction and hit sent and it should give you an option to type in a tracking number and just type in the tracking number that was provided to you by the post office, ups or fedex.
O yea one more thing. It would be a great idea if you took real pictures of your game with a piece of paper that has your listia username on it. That will show people that you have the game and that you are not trying to cheat them out of their credits making them trust you more which will give you a lot more bids and a lot more people that will actually click watch to watch your game and see how high the bid goes and if they want to bid or not.