The Upper West Side is a mix of ornate 19th-century landmarks, solid pre–WWII apartment buildings, well-worn tenements, and some outstanding cultural institutions, including Lincoln Center [1] and the American Museum of Natural History [2]. The neighborhood is also known for its feisty liberal politics, love of culture, and upper-middle class, including an especially large quotient of doctors, lawyers, writers, actors, musicians, dancers, and intellectuals.
Today, the best streets for wandering are Broadway and Columbus Avenue, both lined with a multitude of shops. In comparison, the streets running from east to west tend to be quiet and almost exclusively residential.
Links:
[1] http://www.moon.com/destinations/new-york-city-long-island/manhattan/upper-west-side/lincoln-center
[2] http://www.moon.com/destinations/new-york-city-long-island/manhattan/upper-west-side/american-museum-natural-history