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.
Several databases allow you to make lists of companies within a specific industry or business at a variety of geographic levels. Larger organizations or businesses will have more information; small companies may have only contact information. Use this list making feature to identify competitors, potential collaborators and target markets.
Most of the company profile sources such as Hoover's, Company Dossier and Company Profiles will list 2 to 5 key competitors.
Your marketing plan may be bases on a new or existing company or product. You can find articles in business magazines and trade publications on both companies and products. The best sources to start are ABI and Business Source Premier.
Using Google and other Search Engines