You don't say where you are in Maine, but am sure you can find a guided tour to NYC by checking in the travel classifieds in your local paper or doing an online search. That said, should be equally easy to get down to NYC by train, plane, or bus on your own steam, too. Once you get there, you can take the subway to Yankee Stadium. More info, plus a section about tours of the stadium can be found here: http://atmlb.com/eCAWPn