This video covers using Auxiliary Input Tracks to process and control several tracks at once. This video demonstrates how to set up a sub-mix and how to process the audio on the sub-mix.
This video covers how to set up effects with sends and auxiliary inputs as effects returns. This allows you to add effects across multiple tracks using one effect plug-in. This video goes into detail of how it works and how to set it up. It also covers mini send faders in the mix window.
This video shows you a quick way to clean your audio tracks with Strip Silence. This removes areas where the audio is not playing anything (although there still may be noise or hum from instruments).