Public companies are required to file documents with the Securities and Exchange Commission (SEC). Here is a brief summary of some of the documents:
10-K - annual report filed 90 days after a company's fiscal end. Includes financial statements, properties owned, legal proceedings, description of business and directors and executive officers. Provides Management's Discussion with statements about plans, beliefs and estimates. Check date. 10-Q may be more current. The 10-K is not the same as the glossy annual reports distributed by companies as a marketing tool to attract investors.
10-Q - quarterly report filed within 45 days of a quarters end. (3 per year) Not as extensive as 10-K.
20-F - annual report filed by foreign issuers similar to 10-K. Must be filed 6 months after end of company's fiscal year.
8-K - reports on unexpected events and corporate changes that would be important to investors or the SEC. Time frame for filing is within 8 days of event or change.