How do you get voices in your movies?
To put voices in your movies, all you need is a microphone. Or you can always ask for voice help on the official bulletin board and all you would do is send them a script of what you want them to say.
After you've created the voices or had someone do them for you, you simply put the voice file (such as joe.wav) in the voice track of your movie editing software. Windows MovieMaker is popular because it's free and is usually on the newer computers in your Program Files folder (under Movie Maker).
You can always take that one voice clip and break it up just as you would a movie clip. That way, if you have a Sim saying five sentences but those sentences are not all together, you can just clip the file in your editing program and then re-open the master file and use it whenever your Sim's next sentence comes in.