These are common types of information sources for market research:
Industry Associations
every industry has an association who cares about collecting information and data about that industry.
Government Data
the U.S. government is the single largest collector of data about the U.S. economy and industries
Some agencies you will probably use data from:
U.S. Census Bureau
Bureau of Labor Statistics
Bureau of Economic Analysis
Small Business Administration
Newspapers and News/Opinion Magazines
tend to contain investigative journalism as well as commentary/editorials. They often explore current events or ongoing debates in society. Some showcase a variety of perspectives, while others tilt in an ideological direction. Others are intensely ideological or partisan, but they still fall into this general category.
reputable & specialist publications (like The Economist and The Wall Street Journal) will report on market conditions, policies and regulations affecting industries, and more.
comprehensive accounts of a particular industry, containing a depth of information, facts and statistics (source).
emerging trends, financials, major companies, market share, and supply/demand chain are examples of information that can be found in industry reports.
Trade Publications
these keep professionals up to speed on a given industry’s trends, debates, news, professional development opportunities, and best practices. Under-utilized source type.
Scholarly or journal articles
articles about research written by scholars that are reviewed by other scholars before they're published in academic journals
You can learn about recent research in your field and develop a broader understanding of your product/service space (source).