The put in is off a concrete boat launch, boat traffic will give you some nice swells, otherwise its a very smooth paddle.
There is so much to see, a great view of Whiteface Mountain and McKenzie Mountain, birds, turtles, etc. There are some beautiful houses (they call them Camps) around the lake and on the islands in the center. There is also camping facilities on some of the islands, but I did not visit those.
The entire trip following the perimeter, with a bit of criss-crossing to see the islands is around 12 miles. Very serene and worth the trip.
Plenty of places to stay in village of Lake Placid. We stayed at the Golden Arrow Inn on Mirror Lake. Fantastic resort with rooms right on Mirror Lake.
I-87 to US-9 to NY-73