You can get almost all of your daily shopping needs met in Nizamuddin. The only exceptions to this are probably music, electronics and good paper products. But there are other great markets nearby for these sorts of items. One of the shops I frequent is run by Rajesh. He supplies me with bottled water, dry food goods, and even fresh chapattis to order. Sort of the 7-Eleven of Nizamuddin, Rajesh's store is open long hours each day.
Just down the street is my vegetable-fruit man. He's always there on his corner. He sets up around 8am every morning and is still selling until 8 or 9 pm most evenings. Everything is fresh and most of what he sells is grown in India. Alas, the mango season has ended, but nice apples and pears from Kashmir are starting to be available.
Another stop I make about every other day is to the "Mother Dairy" store. My Dood Walla is almost always in good spirits, even though his days are long ones. He's open from about 5am until around 8pm (although he always takes a lunch break from 2-4pm). His shop sells everything from milk and Dahi (yogurt), to ice cream and butter. It's all fresh and very inexpensive.
The marketplace includes a Chemist (Pharmacy), Hair Salons, a cafe-bakery that also sells new books, a nice clothing store and even a small toy shop. All of this is only within two blocks of our flat. These shops deliver to your home, or you can purchase items like fruits, vegetables and even brushes and brooms from cart vendors that travel the quaint streets and alleys of Nizamuddin East each day!