Depending on the industry, the amount of information available will vary, As you research, consider:
Industries are often identified using numeric codes - Standard Industrial Classification (SIC) codes and North American Industry Classification System (NAICS) codes. NAICS codes are newer and are replacing the SIC system.
SIC and NAICS codes are very useful when researching industries in databases - many business databases allow you to search by the SIC and NAICS codes.
Websites that provide information on SIC and NAICS codes: