thulbs05

Hi, I am a complete beginner on these matters, i was wondering if anybody can help me. I have converted my movie collection from the hard drive on my pc and want to play these films through my xbox 360 on my 42" plasma. Could somebody tell me what size I need to resize the picture to for it to fill the whole screen when playing back? Also what is the best output format for quality? Also how do I make the file so it plays the whole movie rather than just sections? Any help will be greatly recieved. Thank you.