While it may seem easier to do a web search for information rather than use a library database, you need to critically evaluate web sites. While there are numerous web pages that describe how to evaluate a web site, here are a few that you may find useful:
Evaluation Criteria: The Good, The Bad & The Ugly: Why It's a Good Idea to Evaluate Web Sources
Evaluating Web Pages: Techniques to Apply & Questions to Ask
Professional organizations and associations provide useful and practical information about your potential profession. Here are a few links that you may find useful.
American Marketing Association
Committee to Protect Journalists
Council of Public Relations Firms
Newspaper Association of America
American Journalism Review http://www.ajr.org/
Center for Media and Public Affairs http://www.cmpa.com/
Media Research Center https://www.mrc.org/
Columbia Journalism Review http://www.cjr.org/
FAIR: Fairness & Accuracy in Reporting https://fair.org/
Gallup http://www.gallup.com/home.aspx
Institute for Public Relations http://www.instituteforpr.org/
The Media Institute http://www.mediainstitute.org/
National Council for Marketing & Public Relations http://www.ncmpr.org/
Pew Charitable Trusts http://www.pewtrusts.org/
Pew Research Center http://pewresearch.org/
Quinnipiac Polling Institute http://www.quinnipiac.edu/institutes-centers/polling-institute/
The State of the News Media http://stateofthemedia.org/
World Public Opinion http://www.worldpublicopinion.org/