I am visiting the gray ghost inn for a bridge seminar in Sept. Is there a way to go on a guided hike while there?

yes. even evening sessions on wildlife, birds and more. hikes are varied and the innkeeperess will aid you if you contact her. ;)

I am not sure about guided hikes, but Snow Summit and Stratton Mountain both have maps that show hikes up the mountain(s). They are pretty easy to follow though the hikes themselves are uphill one way and somewhat difficult.