Whether you have an interview scheduled, are preparing your resume or are just starting your job search, company research can help you. You want the basics (important people, what they do, etc.), but you also want to make sure you really know the company, and the sources here will help you with both. Here are some recommended starting places:
The annual report is a great and free way to get to know a company. Public companies are required to submit a variety of forms including the Annual Report to Stockholders (ARS) and 10-K Report. You don't need to worry about the all of the different codes for SEC filings. Just know that when you hear Annual Report it usually refers to one or both of those reports, and you should take a look at it even if the job you are considering isn't a "business" job.
You don't have to be a business major to read and use an Annual Report. Depending on your role, you will find different sections useful. Take a look at Why Job Seekers Should Read Annual Reports for help.
The databases listed here make it easy to find Annual Reports, and they actually get a lot of their information from sources like the Annual Report, but they are also typically available for free. You can still always find the Annual Report (as long as it is a public company) at the Company's web site (look for an investor relations link) or try...
As a student, you have access to subscription-based library resources, but there are also resources that you can use anytime including the Annual Report. Also, try the following for free resources.