Search Google for the company's website. Go to Investor Relations. You will see various documents that the company needs to file (if it is publicly traded) with the S.E.C. (Securities and Exchange Commission). Also look at the Company presentations and Corporate Social Responsibility Reports if available.
You will want to look at the following documents:
You may also get these documents from the following sites:
Annual Report
This is not an official document but more of a PR document. It has nice glossy pictures and financial information but not the legal information that the Form 10-K will have.
Sustainability or Corporate Social Responsibility Reports Not every company files these but they are a useful document if you want to look at what a company is doing in terms of sustainability practices.
These are sites that have reviews about the company by both current and former employees. Look at these carefully!