Here are a few questions to ask when researching a company.
Is the company a publicly or privately held corporation?
Is is a non-profit corporation?
Answer these questions will help guide your research. Public companies will have more available information because they have to report to the Securities and Exchanges Commission (SEC), while a privately held company doesn't have the same requirement to report. Non-profits will have some publicly available information through the Internal Revenue Service (IRS).
The type of company will shape the research process.
Searching Public Records
Business and Property Search
Mergent Online - offers a wealth of detail on items including business description, history, property, subsidiaries, officers and directors, long-term debt and capital stock.
TLO: Comprised of public and proprietary records, TLO is a tool for locating and researching connections between individuals, businesses and assets.