Most Internet job sites are heavy on job postings (although few are actual entry level jobs), yet short on actual employer research. The following are the four sites to visit:
CollegeGrad.com Top Entry Level Employers
Listing of all the top entry level employers in the U.S. and Canada, including projected number of hires and links to entry level, intership, and regular job postings for each employer.
Hoovers.com Companies & Industries
Yes, Hoovers will want to sell you a subscription, but there is still plenty of information you can find for free. Simply click on Company Information, then Company Search, then search for a company (employer), people, or industry. You can find plenty of free information about employers (including general contact info, descriptions, and top competitors) and can often find titles of interviewers in advance of the interview. You will have to pay for the more detailed reports, but the general information is available for free.
Glassdoor ranks employers with ratings from current and past employees, along with ratings of the current CEO. You can also get in-depth salary information provided by those already in the role. However, keep in mind that the salary info is typically for those with several years experience, so it may be overstating what that employer is paying at the entry level.
Yes, and in the end, you still need to Google the employer. The first three links above will help you know who to research, but your in-depth research will be in simply Googling the employer. You will find their corporate page, but make sure you go beyond it to look at other published information about the employer, both the good and the bad.