Well, in regard to shopping, 5th Avenue is a prime target from 59th all the down to 49th where Sak's is located. Stores including Versace, Gucci and the ladies' Louis are located there. And then like I stated before, Lexington Ave has some cool stores, especially around 59th... that's where Bloomingdales and Diesel are located, if you need some awesome jeans. Soho is also pretty famous as you know and also Union Square, both of which are pretty sweet. But I'd say neglect Union Square if you haven't been to Soho. Check out this website:
http://nymag.com/visitorsguide/shopping/destinations.htm
As for Restaurants, people have told me to avoid the theatre district, which is between 45th and 51th along 7th Ave. However, I have been to places there before and it's not thaaaat bad and not expensive. If you feel like some Italian, the only trustworthy ristorante I know of is La Mela in Little Italy... and from what I heard it is indeed the only place in Little Italy. I thought it was fantastic and it's particulary inexpensive. Nick told me about Tribeca Grill on the border of Tribeca/Soho, and he apparently thought it was great. I've never been there. And then if you're a major Sushi fan and have loads of money to spend, Nobu is the only place (so I've heard). I hate Sushi.
And if you're planning on going to Chinatown, let me know. That's quite the experiance.