Google maps mashup includes data on population, housing cost, housing market, schools, safety, health, climate, income/work, and age ethnicity for the continental US.

annoyingly, their "explains" don't say where the data comes from, so it's hard to know how up to date it is. However, it's neat.

• Mapping studies of criminal justice population concentrations, including adults and juveniles going in and out of prison and jail; people on probation and parole; and, juveniles in detention.
• Graphics and other charts of administrative, political, social, educational, and other boundary aggregations, such as school districts, city council jurisdictions, neighborhoods, or police precincts.
• Supportive contextual maps of socio-demographics, such as single parent households, disconnected youth, home ownership rates, poverty, income, and many other census bureau statistics.
• Maps of other government health and human services, child welfare, and labor populations, such as TANF, Food Stamps, Medicaid, and Unemployment Insurance recipients, as well as Foster Care clients and reports of Abuse and Neglect.
• Mapping studies of prison and jail expenditures.
• Spider mapping analyses of probation and parole caseload distributions.
• Maps of geographic and neighborhood overlaps between criminal justice and other government client populations.
• Prisoner reentry mapping studies.
• Maps of community institutional networks, such as the location, capacity, and performance of schools, or government institutional networks, such as federally qualified health centers.

Why public housing, once the scourge of the city, now is a vital part of its life and its future.

Encyclopedia of housing / Willem Van Vliet--, editor. [0761913327 (cloth)] Thousand Oaks, Calif. : Sage Publications, c1998.
Call#: Van Pelt Library Reference Stacks HD7287 .E53 1998

Encyclopedia of urban America : the cities and suburbs / Neil Larry Shumsky, editor. [0874368464 (set : alk. paper)] Santa Barbara, Calif. : ABC-CLIO, c1998.
Call#: Fine Arts Library Reference HT123 .E5 1998

Long signed articles with bibliographies. Topics, people, places.

Encyclopedia of urban cultures : cities and cultures around the world / edited by Melvin Ember and Carol R. Ember. [0717256987 (lib. bdg. : alk. paper) ] Danbury, Conn. : Grolier, c2002.
Call#: Van Pelt Library Reference Stacks HT108.5 .E53 2002

Encyclopedia of the city / edited by Roger W. Caves. [0415252253 (alk. paper) ] London ; New York : Routledge, 2005.
Call#: Van Pelt Library Reference Stacks HT108.5 .E63 2005

Greenwood guide to American popular culture / edited by M. Thomas Inge and Dennis Hall. [0313308780 (set : alk. paper) ] Westport, Conn. : Greenwood Press, 2002.
Call#: Van Pelt Library Reference Stacks E169.1 .G7555 2002

 Follow up to Handbook of American Popular Culture. Four volume set includes long detailed articles detailing the scholarly study of popular culture including extensive bibliographies.

Khan, Namir, 1955-. Healthy cities : an annotated bibliography / Namir Khan, Willem H. Vanderburg ; with the collaboration of Lynn Macfie ... [et al.]. [0810840340 (alk. paper)] Lanham, Md. : Scarecrow Press, 2001.
Call#: Van Pelt Library Reference Stacks HT119 .K43 2001

Annotated bibliography on topics about Cities 

Free Registration Required.

Information is at the sub-county level, but only one level beneath county, generally, so Philadelphia is broken only into Planning districts.

Funded by a 3-year grant from the William Penn Foundation, the Metropolitan Philadelphia Indicators Project combines two types of information to illuminate conditions and trends in our 9-county region (defined as the central cities of Philadelphia and Camden along with the Pennsylvania counties of Bucks, Chester, Delaware and Montgomery, and the New Jersey counties of Burlington, Camden, Gloucester and Salem). The first is a set of social, environmental and economic indicators that portray the quality of life in the region’s communities. The second type of information comes from an annual household survey conducted by Temple’s Institute for Survey Research, asking respondents across the region how they assess the quality of life in their communities. Tracking over time the changes in the indicators and in the survey responses, we can better understand how citizens’ perceptions relate to the changing conditions on the ground.