The Securities and Exchange Commission (SEC) requires publicly traded companies in the United States to file annual and quarterly reports. The quarterly report, known as Form 10Q, contains information about the company's financial operations during each of the first three fiscal quarters in a given year. (A company doesn't need to file a quarterly report at the end of the fiscal year, because that's when the annual report is released.)
Form 10K, which is the annual report, contains a much more comprehensive overview of a company's financial operations. It's released at the end of the fourth quarter of the fiscal year and includes information on the company's structure, shareholders, business activities, assets, and liabilities.
An additional disclosure form you may want to look at is Form 8K. A company is required to file Form 8K with the SEC if it undertakes structural changes, such as a merger or acquisition, bankruptcy, or election of new board members. Form 8K may contain important information regarding the company's future plans. So, where can you check out a company's annual report or Form 8K? Perhaps the best resource for this type of information is EDGAR. It includes comprehensive SEC filings. You may need a subscription to access it.