unsure of you current age/education, but for college and post-grad your school probably has an online library that gives you access to the paid databases of papers/articles. i mainly wrote papers for psychology and economics, i used BMI Research, Euromonitor International, MarketLine and Factiva a lot.

lit review should summarize what you've read on similar/relevant thesis (who at when, how did they test and what did they find) - and these probably will be quoted later in your paper esp when you explain how you formulated your hypothesis, and what you referenced to build your study method on.

A literature review is just a summary of what everyone before you (or at least the major people) have written about your topic. The place to start would be your school's library. If you have any other questions, I'll be happy to help. Good luck!