You can find company information in a number of the library's business databases, a few best bets are linked above. It's helpful to know your company's ticker symbol (an abbreviation used to identify publicly traded shares of a particular stock on a stock market) before you begin searching.
A few things to know:
EDGAR Company Filings Database: performs automated collection, validation, indexing, acceptance, and forwarding of submissions by companies and others who are required by law to file forms with the U.S. Securities and Exchange Commission (SEC)
Thomas Register of Manufacturers (Thomas Publishing Company): search across 607,000 manufacturers across the U.S. and Canada. A good resource for business-to-business information needs. Also provides a means to trace a brand name back to its manufacturer.
Fortune's Global 500: an annual ranking of the top 500 corporations worldwide as measured by revenue
-a video tutorial by Chad Boeninger, Business Librarian at Ohio University Libraries