Most companies will post their primary SEC filings, such as the 10-K reports, in the investor's section of their company webpage.
It's helpful to start with general overviews of a company. Background information will make it easier to search for company specifics on the Internet or to find articles in the business press.
How can you investigate the perspectives of various stakeholders on a specific company? First, search for articles on the company in the key business databases. Second, look for webpages from various stakeholders or groups monitoring companies. Explore social media sites as well.