First: there's a JTB tourist information bureau in the airport with some maps and brochures - I recommend it, and visiting the ATM, as Japan is much more a cash economy than the US.
Everyone's right about the Hilton Narita NRT - I use it with some regularity for connections and the like. You'll likely not get much of an ugrade, and there's not much to an upgrade anyway. As for the "special" hotel restaurant on the second floor, it's absolute cr@p and extremely overpriced. If you get a breakfast incuded, though the coupon may say Continental, nobody checks and you normally get to access in the lobby restaurant to the whole megillah, as they say in Japan.
This hotel is one of the best deals for an award, as it's only
10k HH points.
The free shuttles are nice, and Narita is not a bad place to walk around, as the
Narita-san Shinsho-ji temple complex is quite colorful. Wait a while around the main temple, and when you hear the gong, you will see a procession climb the stairs and you will observe a very colorful and interesting ceremony of the burning of "goma" (you will be wolcome if you remove your shoes and are respectfully observant.) If Spring has sprung, the gardens are quite beautiful, and on weekends you may find a shakuhachi and koto concert happening near the picturesque lake. We had these pleasures with the beautiful Fall colors last year - a most relaxing and lovely day!
The way there and back through Narita-shi (city),
Ometesando, has quite a wide selection for food - much cheaper than the hotel! You can always stop for a cool one at the
Barge Inn (also on Ometesando,) which I think is owned and operated by some Virgin refugees. (You can get shuttle and airport buts timetables at the hotel, and sometimes a map of Narita - I'd get one at the airport.) Cheap eats and good coffee at
Kohikan on the same street, as well as Japanese and Indian food. The town specialty is eel.
From Narita-shi, you can train it to
Sakura for a walk around the historic castle grounds (no castle any more) and
National Museum of Japanese History. Take the train to Sakura, there's a map outside of the train station, and a ten - fifteen minute walk. There's a reasonable restaurant in the museum. I can't recall what we paid for admission, but it was reasonable, and we got some English electronic guide headsets (handy, because there's not quite enough Romaji signage in the museum.)
Boso-no-Mura is nice too, recreations of ancient Japanese village life, interactive and free (closed Mondays, as are many museums in Japan.) Take the Narita Line train to
Ajiki (two stops) and the Ryukakuji-dai Shako bus and ask to be let off at Boso-no-Mura. From there it's a five minute walk.
You can always got to Tokyo, of course - it takes a while, and the faster you get there the more it costs. NOt to mention Tokyo ain't cheap either, but it is nice - be sure to get a guidebook or maps and watch your time.