I found a sound operator's posting on the internet of all of his responsibilities.  While reading it, I realized there is a long list of responsiblies fof a successful sound ministry.   If you have your own points to add, please comment on this article.

Techie Stuff:

    1. Sound booth kept clean and dusted.  No church bulletins from three years ago!
    2. Maintain an up-to-date inventory of all church-owned audio equipment.
    3. Perform maintenance checks on all audio gear.  This includes testing cables, re-seating loose plugs, and verifying components work properly.
    4. Kept booth stocked with blank media for recording and batteries for wireless equipment. This includes remote controls!
    5. Fix or replace damaged audio equipment.  When needed, arrange for a qualified company to fix damaged equipment such as a mixer or monitor.
    6. Have backups for most common items: mic clips, mic stands, direct boxes, etc.
    7. Have a tool set for fixing common problems like re-wiring an XLR cable.  Wire cutters, soldering iron, regular and philips head screwdrivers, electrical tape, duct tape, pliers, a pocket knife, small wrench set, soldering material, and a small hammer. 
    8. Recognize the extent of the sound ministry; portable audio equipment in the youth rooms, ceiling speakers in the nursery or any other room that uses them.  In short, it if makes sound or amplifies sound in your church, it's the responsibility of the sound ministry.
    9. Check all rack-mounted equipment for solid connections, incorrect switches, and proper power.  Check the mixer, too.
    10. When using a house EQ with tangible faders, check that it's set properly.  Many EQ's are now set via software.

Rehearsal Time:

    1. Some sound ops like to attend worship team rehearsals so they can practice settings eq/volume levels for new songs.  Some worship teams has a "last minute" practice session before the service where they run through all their songs.  This can be a great time to study any new songs they practice.

Pre-Service Time:

    1. Set up the stage.  Set up microphone stands, music stands, instrument stands, and move equipment if necessary.  Plug in all cables, direct boxes, monitors, and anything else that will be used.  Ask musicians if you can set up their instruments.  If you are a musician yourself, they usually don't mind.  Note location of where cables are plugged in for labeling the mixer.  NOTE: place microphone stands, instruments, etc., in locations that provide good line-of-sight for the congregation and also provide proper good mic locations with regard to sound isolation from other instruments and monitors.
    2. Perform a proper sound check for each sound source (microphones, instruments, CD's, etc.). Test/set these individually then mix as a group such as during a rehearsal of a worship song with the worship team.
    3. Fix any broken equipment or swap with replacement and fix after service.
    4. Have sanctuary ready 15 minutes before congregation members come in. 
    5. Set proper monitor levels.
    6. Add in effects where necessary (a little reverb can smooth out pitchy vocals)

Service Time:

    1. Have a service outline of songs and events in the sound booth so you are always a step ahead.
    2. Tweak volume levels where appropriate.  Same with EQ though not likely at this point.
    3. "Run sound" - you know what I mean.
    4. Create a music mix that you would be proud to re-play to your family.  Create the proper music mix and the correct volume for leading (yet accompanying) the congregation.
       

People Skills:

    1. Learn how to handle complaints from the congregation - usually "it's too loud" or "I couldn't hear the ___"
    2. Learn how to handle complaints from the worship leaders and others on stage - usually pertaining to bad monitor mix or miscues.
    3. Learn how to talk frankly (yet gently) with worship teams to correct or prevent problems.
    4. Recognize that a service is a time perfect for spiritual warfare.

Head Duties:

    1. Recruit volunteers.  Just because Bob has been doing sound for the last three years doesn't mean he wants to continue doing it.
    2. Develop existing volunteers by providing mentoring relationships or holding occasional evening training sessions such as "how to set EQ for drums and guitars."
    3. Support and encourage volunteers.  Everyone has good and bad days behind the mixer.  Praise them when they do well and help them when they don't.  Pass on compliments when you hear them.
    4. Inform sound operators if their volume settings were too high or low.  Investigate why it happened and what can be done in the future to prevent it.
    5. Ensure that sound systems are properly managed during worship services and other events.  This means make sure your sound operators showed up on time, performed their duties to the best of their abilities, and provided a good listening experience.
    6. Hold team building activities with your team members.  Getting to know each other will make your lives more enjoyable.  Include worship leaders and worship teams from time to time.
    7. Attend church staff meetings.  I know you hate meetings but it helps in times of trouble or want - like a new mixer.
    8. Stay on top of the latest developments in sound technology, techniques, and equipment.  You are looked upon as a sound expert so you best know your stuff.
    9. Provide guidelines of expectations for your volunteers to follow.  Running sound isn't just turning on the mixer and setting all the volume levels just once.
    10. Provide rules / expectations for anyone borrowing equipment such as "we need to borrow a mic and a cable for an outreach event."  This might even involve a short "how to wind cables" lesson.
    11. Keep an event list of special weekend services, weddings, funerals, concerts, and other events so sound operators are assigned to all events, not just the church service.
    12. Act as a buffer between sound operators and others during times of tension. 
    13. Have plan for providing assistance for the hearing impaired.
    14. Personally run sound for some non-service events to build your experience.  This will help you and you can then help others.
    15. Stay up-to-date with worship teams and service event coordinators so each event has all the proper equipment.
    16. Depending on how your church operates, schedule operators for all events (services, weddings, etc.).
    17. Provide training or training resources to the volunteer sound operators either as "brush up on skills" or as a 101-level training for people interested in working with the sound ministry.
    18. Train players and singers in the basic elements of audio, like proper microphone usage and monitor volume setting.
    19. Understand that it's your job to oversee the Sound Ministry.  This means helping, training, learning, and leading.  You have been tasked with a flock of volunteers.  Minister to them so they can joyfully serve.