Sounds like a good idea, huh? Recently I won a new book from 24/7MOMS by Keri Wyatt Kent called "Breathe". It's a great book for any stage in motherhood for the one simple fact of helping all of us remember to slow down. I was encouraged that the little things I'm doing now (saying no to certain things, staying home all day some days, etc) are all helping lead me down the path of simplicity (or Sabbath Simplicity as she calls it) and, hopefully, not getting over committed in the future.
At one point in the book Kent talks about where we find our value and as a stay at home mom sometimes it's really hard not to commit to something just to show that we aren't "just staying home with the kids". She says, "It's as if we believe that our value comes from what we do...The only problem is, it's a lie! Our value comes not from what we do but from who we are. And we are beloved children of God."
So, I challenge you, as the new school year begins and your children are getting days/months/years older, to really look at your schedule and those letters asking you to do this or do that to just sit for a minute and ask Him what He would have you do or not do. You may find a little peace in this sometimes crazy, hectic world.