I have always signed my kids up for day camp, swimming lessons, a couple of classes of something or other, soccer and at least one week of a lake vacation. In recent years and as my kids are getting older we have done swimming lessons for the younger ones, soccer, and the week of vacation. Two years ago we bought a camper parked it on a lake nearby and we try to go up there every other weekend or if possible during the week. The main activity is fishing followed by swimming and lying around! To complicate things my oldest has 2 jobs this summer and the next 2 are reffing soccer games which all falls on the weekend. WHY do kids have to grow up??? Enjoy your summer with your little kids...it changes fast. And don't schedule too much.
My kids had the time of their lives one summer when all the neighbor kids got together day after day looking for grasshoppers in the field behind our house. FREE and fun for all!