J.B.
Hi,
Two web-sites to check out are www.vrbo.com and www.vacationrentals.com. We just rented a cottage this summer in the Traverse City area on a smaller lake called Island Lake. It was quiet and beautiful. There are tons of cottages on these websites. I reserved ours in January sometime and there were plenty of weeks available in summer. Good luck, and hope it's fun!
J.