A company's investor relations webpage is often an excellent source for annual reports and other announcements. You can locate by Googling the company name along with "investor relations". These pages also may have links to investor calls, where you can listen to company executives talking through results with analysts.
You can also find detailed information by reading reports submitted to the government. The SEC requires all companies that trade on U.S. stock exchanges to file annual reports, quarterly updates, and other disclosures; these are heavily used by company analysts.