HAHAHA, I was just gonna post this one. I live in Petoskey, Harbor is 10 mins. away. If anyone wants a guide, send me an e-mail, i'm always looking for an excuse to go up there.
M119 is a 20 mile stretch from harbor to cross village, 4 miles to sturgeon from cross village (just take a left at the only stop sign, and you'll find the beach). Takes about 45 mins one way (yes, it has that many corners). I'll warn you now, it's about a lane and a half wide for most of it, if you find traffic, your stuck behind them untill you either pull over for 5 minutes and let them get ahead, or they pull over and let you pass. If you come up to a car going the other way, you need to slow down, get as far over to your side as possible and hope it's not something really wide.
as for the course layout: 2 hairpin turns (one of which is called "Devil's Elbow") along with many mid-slow speed corners. Traffic usually isn't too bad, but keep in mind, your going twice the speed of everyone else, you will catch up and be stuck behind someone. Just hope they are nice and pull off to the side and let you pass. At night you can go faster because if there is oncoming traffic, you can see their lights and slow down.
Sturgeon bay is a good photo opportunity at sunset, lots of sand and a little water against a backdrop of sand dunes and a forest. Also, if you have time in cross village, stop by legs inn, you'll see it, it's the only thing in cross village (except for the gas station, but that's a little harder to find). They have GOOD polish food there, and it's... interesting... inside.
Usually, i'll drive up to cross village, stop at the gas station for a pop, and go back down M119 to harbor and home. The road to sturgeon is worth driving, but i've been on it too often (and it's only 4 miles of mostly straights).
Pictures are here