This is probably an obvious question, but I thought I'd ask it anyway....
Do I have to edit all video in another application like Final Cut Pro or iMovie before importing it to After Effects?
Say, if I want to chop up the video to fit pieces of it at various locations in my movie so it matches up with the music track I'm working with? And then import those video pieces and place them as desired?
Hehe, I've "edited" half hour pieces in AE... :-) It's absolutely possible, but as Todd said, using an NLE such as FCP or Premiere is usually preferable, especially if your work needs to include audio, which until this day AE does not play realtime. It's also a matter of what footage types you use. I can e.g. perfectly work interactively with my home camera HDV stuff, as apparently MediaCore likes it, but if I had "the wrong camera", the situation would possibly be a different one. Your mileage may vary, as they say.