Click on one track and you will see that it is highlighted. Hold the shift button down and select each track that you wish to adjust. Also, using a bus for each set of instruments is helpful and easier, that way selecting tracks is less hassle because well, there's less to select. You can also do the same thing when adding plug-ins and effects as well. Select all the tracks you wish to have a certain plug-in or effect and drag said items to on of the highlighted tracks and it will place all of them on the highlighted tracks.
Hope this helps!
Will
