According to Season and Activity you'll do.
I always bring an empty fold up bag to put my items I bought while shopping. And North Conway is a place to go shopping folks! Extra sweat shirts and jacket in the Fall or Winter. Layering is the way to keep warm & if you get hot you can remove a layer.
Also extra gloves incase one pair gets wet. Mosquito Repellent in the Spring & Summer. They are AWFUL in New Hampshire. Many lakes & ponds for them the thrive in! I always bring my battery charger & an extra memory card & battery. If you're a camper or hiking ... you know what to bring. If not ... check out the many website for the list of items to birng. Extra money & my credit card .... hahaha, don't leave home without it!