Not having spent much time in the area I was pleasantly surprised at all the good food, and especially good grocery stores!!
One in particular blew me away...
Westside Market on 110th and Broadway is a specialty grocer that serves up the best produce I've found almost anywhere in the city. Super fresh blueberries @ 2 for $5 is a great deal! Plus mangoes, pineapples, avocados, strawberries you name it!
As for their beer selection - they've got everything under the sun - local brews, imported, buy it as a six pack or mix and match to please everyone in the house.
They also have an extensive cheese selection and fresh baked pies - even cheesecakes from Juniors!
Westside market also has a location on the Upper West Side and Chelsea - haven't been there so not sure if the prices are as good...but it's worth a trip.

While you are up there, grab a latte from Oren's Daily Roast to taste some real joe.