One of the things I love about movies is that they usually have the extra behind the scenes stuff. The best one I have seen is the extras on the Star Trek DVD (J.J. Abrams version). He walks you through all the trick shots they did, for example when Spock enters the elevator and then gets off on a different floor, but it's all one shot, they green screened half it so it looks like he changes floors but in reality he didn't.
Also included in the extras section is a bit about how they animated the Enterprise in the shots where the ship is in space. It's really cool to see how they turn off the lights and turn others on until they like the way the ship is lit.
Definitely watch the extras if you have time. It's really entertaining.