For first-time visitors you should visit the Adirondack Museum in Blue Mountain Lake. If you get to Lake Placid there's the Olympic venue, ski jumps, and bobsled run.
We're not into the Lake George scene, but prefer more rustic DEC cg's. For a full hookup, pull-through site there's North Pole Resort (100 Acre Wood side) in Wilmington outside of Lake Placid. You'll follow the Ausabe River, a big fly fishing stream.
From NE Pa I'd probably go north on I87 and hit the Finger Lakes on the way back. Letchworth SP has the Mt Morris dam and Genesee River gorge. Watkins Glen has a nice gorge walk. There's also the Corning Museum of Glass and numerous wineries to visit. There's a brand new cg being built (Twilight on the Erie), check out their Facebook page. They should be open by September.