Here are a few resources related to the role of small business and local retail in promoting quality urbanism:
Street life stories explore some of Chicago's archetypal main streets
A "Remakery" is a social enterprise that teaches repair. See this example from the U.K.
Are Co-ops the key to retaining small business and active street life? Here's a directory of Co-ops in Washington, D.C.
Some research is devoted more specifically the role of streetscapes and active frontage in successful urbanism:
The City at Eye Level is an international network devoted to "public space with human scale, interaction and human experience."
Streetscape Territories is a research project devoted to "streetscapes as protagonists"
The Project for Public Spaces has resources on active frontages
Vacant New York maps shuttered storefronts
Some big box retailers are trying to be more human scaled....not exactly local retail, but are these formats contributing to more active street frontage?
Storefront Survivors is a research project where students at Hunter College interviewed small businesses.
Vanishing New York is a heart-felt resource on the loss of small business
The City of Chicago tries to support small business (although it's unclear how small these businesses are, and whether they contribute to interactive frontages)
This article in the New York Times characterizes the issue nicely: New York’s Disappearing Storefronts