If you want some simple apple picking fun, try Dowse Orchards in Sherborn.  They have a nice farm stand and you enter the orchard on a dirt road off North Main St.  Beautiful orchard and views as you're picking.  Simple fun, just pick and pay for the apples you pick by the pound.  No entry fees, trains, or petting zoos - almost the opposite of Marino's Lookout Farm in Natick.  Delicious cider and pumpkins at the farm stand too!  Great fall family trip.  We have gone here every year for the past 6 years and it is perfect!  Try the C&L Frosty for lunch after - great ice cream and basic lunch fare.