Company web sites can provide a wealth of information, particularly for public companies. Look for press releases, investor information and financials, including presentations and events and filings such as SEC filings, annual reports or corporate social responsibility or "community" reports. Use information from the company carefully and watch for bias or an overly-optimistic interpretation of factual data.
For public companies, you can try a Google Search using the name of the company, plus the term "investor relations". Company financial reports, such as 10-K and 10-Q filings are often readily available on public company sites.
Databases and resources for company research: