OT-Grand Haven Vacation

Hello again MGoCommunity:

Next week, my entire family has rented a cottage on Lake Michigan in Grand Haven.  For those of you who have visited or lived in that area; What would you recommend I check out?  I am looking for both kid/family friendly ideas as well as more adult orientated things for my wife and I to do (I mean, grandparents love to babysit for free, right?).  I am interested in restaurants, touristy attractions, golf, etc.  

Edit: We do plan on bringing our bikes.  I know there are some trails there.  Any recommendations in that department?