Companies often provide valuable information online, including their annual reports to stockholders. Look for: Investors
These links are usually at the very top or very bottom of the company's home page
All companies, foreign and domestic, that are traded under the jurisdiction of the U.S. Securities and Exchange Commission are required to file through EDGAR. Free access to these 20 million+ filings.
Many countries have business registration equivalents to EDGAR filings. Reporting requirements will vary and it can be difficult to locate the correct site. Here are some examples of international business registration websites. Keep in mind that most business reports will be in the national language of the country they report to.