This is a beginning for researching companies. Why check out a company? Find out if you really want to work there. If you get an interview go in with information you can discuss with the interviewer. Researching will help you create the questions you want to ask during your interview. Check out what salaries are paid in the industry you are considering. This is going to help when you negotiate that job offer. When you write your cover letter it is best to address it to a person. Your research may reveal whom you should be sending your resume to. Again, knowledge is power.
Your public library is a great place to research companies. The Reference Librarain can help with your search. Many libraries have access to a great database, ReferenceUSA. ReferenceUSA is available to libraries, educational institutions and government agencies. You can check online ReferenceUSA to see if your public library is licensed to access this database.