Great time of year time visit that area, never fished for Salmon so I can't help out there. My parents lived in So NH I took my GF (now wife) back east to meet them in early Oct. A fun drive would be the Kancamagus Highway that goes from western NH to Conway in the White Mtns. Be sure to visit North Conway, we rode on the Conway Scenic Railroad, it was mid week & a buch of old farts (of which I am one now) were on the train taking in the scenery, as we rode past the high school, the football players on the field shot us "the moon", it was funny to see all those fuddy duddies crank their face around "did you see that".
Another experience would be to go to the Fryeburg Fair
http://www.fryeburgfair.org/ just across the Maine border and there should be some Lobster Shacks around there, cheap lobster, mmmmm!
My father had an Old Town canoe, my GF & I did a trip on an easy flowing river. The GF is a born & raised SoCal, the autumn colors were reflecting off the water, I said "well dear, what do you think?" She said "It's, it's just like Disneyland" - *