First of all, you need to pack all your things that you feel will be required during your stay in Sanbornville, New Hampshire. Make sure you take a comfortable pair of shoes with you, as this will greatly help you in remaining relaxed even after long walks. Also, you can consider packing casual clothes, as you will never want to dress formal while visiting different places in the city.
You should also book your flight well before your departure date. This will most probably allow you to save some costs, as many airline services offer discounted prices on advance bookings. Also, you can compare prices for different airlines and choose the one that falls in your budget.
Book you hotel room in advance. If you are visiting the city during the busy season, then you should have a hotel room booked in advance, or you may not be able to find good accommodation after your arrival in the city. You can also talk to your travel agent for that purpose and they will help you in finding some of the best accommodations in the city, with low prices.