We did a New England fall colors trip a few years ago and had the same question. We did an internet search and got all the information we needed to include when to go and where to go. We found a sort of email newsletter that we joined that provided us with periodic reports on the best places to see the colors and when those colors were supposed to peak. We were able to go into their archives to see many different photos of many different areas in order to decide where we wanted to go. That was one of our best trips ever.