Video is simple, you should have an S-Video port on your laptop. Buy an s-video to RCA (just the yellow video one actually) converter (look online, its about $20 at Radio-Shack and $5 online). You also need a 1/8" or headphone jack cable that turns into audio RCA. Also easily found online.
Then you go to display settings and set up dual moniter settings. Drag the movie program (like DivX) over to the dual moniter side. If you hooked it up right you should see your plain desktop on your tv screen.
Laptops have a switch screen mode thats was designed for doing presentations, it's most likely a function key (one of the blue labeled buttons). You might need to use this, but I think using that button it will either have just your display on the TV and not on the laptop, or both. Depends on the OS and PC I believe.
Good luck.