1. Search the company in the databases on this page.
2. Look at the company's website.
3. Search for newspaper, journal and trade publication articles about the company.
You may find it useful to know what type of company it is: public or private, a subsidiary or a non-profit.
As a rule the larger the company the easier it is to get information on it. There is a lot more information and analysis available for public companies than for private companies or subsidiaries
It can be helpful to consider what type of company you are seeking information on:
Public listed / quoted
Private / proprietary / unlisted
Non-profit organisations / Not-For-Profit / NGO