Serious Eats - seriouseats.com

1) you should repost in the nyc talk section so more new yorkers will see / respond to your post.

2) for a first timer i would hit the best of the best if you can - like blue hill or babbo... they are both formal but not super stuffy places (in my humble opinion). they are not cheap though.... if you are adventurous you could try to get a reservation at momofuku ko. otherwise, new york times and new york magazine have very reliable critics - you can scan their top picks.

new york city favorites: you must have a burger while youre here - i recommend shake shack. you should also try the pizza since new yorkers pride themselves on that - although myself i am disapointed with the pizza in new york. bagels are also a nyc thing - murrays bagels or h&h are excellent choices.

for more neighborhoody picks - try boqueria (spanish), little owl (american), or falai (italian).

finally for dessert, eileens cheesecake, the numerous chocolate shops (marie belle, vosges, chocolate bar, etc), cupcakes from cupcake cafe, or ice cream - there was a discussion about the best nyc ice cream awhile back on this site, you could consult that list for ideas.

anyway, just some thoughts! hope you enjoy the trip!

As you like Italian food, my reccomendations are:
Celeste - best inexpensive Italian restaurant in Manhattan, and in the Upper West Side, of all places, good wine list, cash only. They make my favorite vitello tonnato.
Otto Pizzeria - I don't mind listening to Mario Batali's Britpop soundtrack here. Great wine list.
Lombardi's - my favorite serious NY pizzeria.
Bar Pitti - another good inexpensive Italian place, in Soho
MOMA's cafeteria on the 2nd floor - good pork chops, pastas, ice cream from labaratorio del gelato. Best inexpensive Italian restaurant in midtown, and run by one of the best restarant groups of New York.

Splurge:
Settemezzo (NB: cash only)
Insieme
La Grenouille - for the classic French food that's hard to find in France. Very old school.

Others:
Cafe Sabarsky (Austrian food, great pastries and coffee, a good museum attached to it)
Cendrillon (Philippine food)
Prune (Elizabeth David style French American food. One of the first places to knock off St John's Bone Marrow on Toast appetizer. Good for brunch also.)
Cho Dang Gol (Korean food)
Yakitori Totto - Japanese teriyaki. You would need to reserve a few days in advance. Open late.
Momofuku Ssam

Shopsin's!
Marlow & sons/diner

Thanks for letting me know, femmebot. : (

I'm jealous that the residents of Ditmas Park will be close to Romy Dorotan's new restaurant.