Start with the Industry Statistics Portal from the US Census Bureau for access to many different data sets. You'll need to know the NAICS (North American Industry Classification System) code for your industry.
The Economic Census (from 2017) covers retail trade, wholesale trade, service industries, construction industries, manufactures, mineral industries, transportation, communications, utilities, and financial, insurance, and real estate industries.
The IRS has a small series of industry-based Audit Techniques Guides to assist IRS examiners in the audit and evaluation of specific industries.
Over 100 industries are covered in the Industries at a Glance series of reports on employment, earnings, and workplace trends, from the Bureau of Labor Statistics.
A small handful of industry, commodity, or service sectors are included among the Commission Publications from the U.S. International Trade Commission.
The Small Business Administration provides links to many Business Guides by Industry, including advice for compliance with government regulations. ** Please be aware of broken links. **
Industry-specific trade data for many major sectors is available from the Industry and Analysis unit of the International Trade Administration, including Automotive Industries, Consumer Goods, and Travel and Tourism.
The number of establishments with employees in each industry may be found in County Business Patterns from the Census Bureau. Data is also available for Metro areas and by ZIP code.
The Official Board offers charts for "the world's 20,000 largest corporations" (registration required)
CogMap is an organizational chart wiki for companies and organizations. Do note that the information is self-reported and almost anyone can edit the content.
