There is plenty of great trout and bass fishing in Maine too.
For the latest local advice, if you're driving down from Boston, Kittery Trading Post in Kittery and Eldredge Brothers in Cape Neddick are well-stocked shops and great places to visit. If you're flying directly in to Portland, try the fly departments at Cabela's in Scarborough and L. L. Bean (the granddaddy of them all) in Freeport.