I'm trying to get from LaGuardia Airport to an Inn in Lake Placid via mass transportation to the greatest extent such a thing is possible and the cheapest way possible. I'm even considering a car service for of the trek as prices seem to be cheaper than those of traditional cabs. Any and all advice welcome. This will be my first time skiing in the Adirondack and I'm hoping I can have a good time sans-car!
From Penn Station in New York, you can take the Amtrak train, #69 The Adirondack to Westport NY and then transfer to an Amtrak Thruway Bus to Lake Placid. Depart Penn station 0830am, arrive Westport 208pm depart Amtrak Thruway Bus 220pm arrive Lake Placid 305pm. Check schedule and prices at Amtrak.com also you can take the Greyhound from New York Port Authority Depot, departing at 830am and arriving Lake Placid at 545pm. You can check schedule and prices at greyhound.com
The Amtrak suggestion is excellent--just be aware that the whole trip is going to involve a lot of transfers and getting yourself and your luggage on/off many modes of transport. Between LGA and NY Penn Station, probably your best bet is the NYC Airporter bus ([original link], $13 each way). And you'll have to take a cab or rent a car to get from the Lake Placid bus terminal to your destination.
If it were me, I'd just rent a car from LGA to avoid hassle and save time. To me, one-seat ride is worth spending a few extra bucks.