I want to work with multiple audio tracks from a screencast. I cannot figure out how. I have several audio files, one from each person that I'm playing with (output from our chat program). And, I have an audio track from the program I'm recording. All are stereo (even the chat -- "Mumble" gives positional information in chat). Nothing is in iTunes or garage band. I've never used either. Don't know how. My goal is to be able to take all these, make sure they are lined up properly (audio tracks will all be off slightly based on when people joined the chat and started talking). Adjust volumes on them separately (the program's audio, and one of the chat voices will need adjusting; the other voices are auto adjusted by Mumble). I cannot even figure out how to import the various audio tracks, let along how to adjust their start times to get them all lined up. Help, please?