To look up the population of a city, look in the blue pages of Martindale-Hubbell or search U.S. Census Bureau's Population Finder. To find out the county in which a U.S. city is located, you can also look in the blue pages of Martindale-Hubbell or search NACO's City-County Search. You could also search the city as the "Feature Name" in the USGS Geographic Names Information System. The Information System will also tell you the city's population, elevation, latitude and longitude.
To find the mayor of a particular city -- or to get basic biographical info on a mayor -- search the Meet the Mayors database posted by the United States Conference of Mayors. For more information, or if that doesn't work, (a) try the city's Web site and/or (b) search a database of articles from local newspapers.
For information on life in a particular major city, check out CitySearch or find other Internet sites using Yahoo! or another search engine. You can find out a lot about the major cities from the tourist guide books sold in bookstores.
To get local business news, check out a city specific business newspaper, such as the relevant Crain City Publication (e.g., Crain's New York Business) or Business Journal (e.g., the Baltimore Business Journal); these publications are often included in online news databases.
To check out a city's economy, see economic indicators posted by the Bureau of Labor Statistics . Mergent's Municipal and Government Manual gives a financial profile of larger cities. You can get annual financial reports filed by cities that issue bonds and their debt ratings through the MSRB's EMMA database. You can also get debt ratings from the individual rating agency web sites listed in the "Debt Ratings" entry.
The tax laws of larger cities are published in the CCH State Tax Reporter for the relevant state. (Note: If you don't have access to the looseleafs, online versions of the CCH State Tax Reporters are available on Westlaw.)
For more specific information, search for entries on selected cities by name.