The company you are researching may be categorized in different industries, depending on the analyst.
Find a similar publicly-traded company and see how they are categorized as an industry. (One place to search for information about publicly-traded companies is Mergent Online.)
Search for private companies in PrivCo. (PrivCo will not have all private companies, but excels in companies preparing for an IPO, or that have been recently involved in a merger or acquisition. You have access to PrivCo through the library's databases, but must also set up a unique account at their site.)
Log in to Esearch before searching these databases
--Use IBISWorld to locate substantial industry reports. In addition to industry reports for the traditional NAICS categories, IBISWorld also compiles reports for their own unique industry categories.
--Business Source Complete (restrict your search to Industry Profile or Market Research Report by selecting those options under Publication Type (about half-way down the page on the right)). Business Monitor reports are available through Business Source Complete.
--ProQuest (under Document Type (about the middle of the page) choose Industry Reports (or Market Report or Market Research) and then search by NAICS code (use only first four digits of NAICS).
--Lexis/Nexis: Choose Search By Content Type from above the search box on the front page. Select Dossier(Company, Executive, & Industry) under Companies. Choose the Industry tab and search by keyword or by SIC code. At the top of the page is an option to choose or browse sources (the source directory). Choose Browse, then choose Industries & Markets.
--Standard & Poor’s NetAdvantage covers a selection of industries. Look for your industry under the drop-down menu on the right-hand side titled Industry Surveys. (Also provides archived reports for select industries.)
--Business Insights: Essentials (select the Industries tab and search by NAICS, or use the search box at the top of the page to do a keyword search.)
--Current Industrial Reports: http://www.census.gov/manufacturing/cir/index.html
--Value Line: Use the search box or look under the Markets tab for Industry Analysis. Offers brief analysis on many (but not all) industries.
--To locate particular journals, newspapers, and magazines search for the title in Ejournals from the library's front page (be sure you're logged into Esearch). (Ex: searching for Wall Street Journal will take you to a link that takes you to the database where you can search all of WSJ.)