You can view my report from last year and see a picture of the sign.
Scroll down to the 3rd picture and click on it. http://www.nogodforme.com/IOA.htm
The shuttle works, only thing is, it leaves after 9am, and they won't be at the park when it opens. Not the worst problem, but it helps to be at the park before opening to get a head start on the crowds. And they need to be waiting at the shuttle 30 minutes before it leaves, because many people show up, and they need to be first in line, because sometimes the bus is full.
I'd think about driving them to SWF before your conferance, then meeting them in the park or picking them up outside. If you both have cell phones, you can do this even if the calls count as long distance. You can drop them off at the Renaissance which is right across the street from the parking lot. It's a huge 10 story resort, you can't miss it. Go here to see directions on how to get there. http://www.nogodforme.com/touridrive.htm