When we went, trips to Ground Zero had become a pretty sensitive issue because of the number of people exploiting grief tourism, making a quick buck flogging nasty plastic Twin Towers replicas, etc. It'd be worth avoiding looking too 'touristy' that day, if you know what I mean.
My advice is to take comfy trainers and walk as much as possible, there's so much to see and explore. Try breakfast bagels in Brooklyn, take the ferry to Staten Island [it's free] for a close up view of the Statue of Liberty.
http://www.google.co.uk/url?sa=t&rc...SMg4BY&usg=AFQjCNEo_K3ESkZQGx4fDi5kun0PF0QUSg
Not for everyone, but I loved going up - and up - the Empire State Building with all its flamboyant Art Deco, knowing I was following in so many famous footsteps.
Central Park is lovely [in daylight, not at night] and you can wander through it to explore places like the Metropolitan Museum of Art, which is a feast for the eyes.
I loved Bloomingdales to browse and pick up souvenirs at all prices. Their iconic Little Brown Bags, which featured in Sex and the City, make great, inexpensive presents. [I use mine as a lunch bag.] I agree with Mam about Macy's - it just felt like any old department store.
Dn't forget to press your nose against the window of Tiffany's to stare in - just don't ask about their prices!
Have a wonderful time - I loved, loved,
loved New York, and I'm sure you will, too.
PS So very sorry you lost your dog, it hurts like hell, doesn't it?