Libraries
Your school library website should offer a wide variety of amazing resources that you wouldn't normally come across in a simple Google search. This includes databases that can offer scholarly information directly related to what you're looking for.
Use Wikipedia With Caution
Wikipedia is certainly a valuable resource. Since it is a wiki, and can be edited by anyone all over the world (editorial guidelines do apply), it should not be used as your ultimate source of information. In addition, most universities and colleges do not view Wikipedia as an acceptable source.
Does that mean you can't use Wikipedia? Absolutely not! Wikipedia should be viewed as a funnel to primary source resources. Most of the articles on Wikipedia are written with several outside reference links at the bottom of the page that will lead you to more acceptable content for citation.
Sources Within Sources
One of the best ways to find really useful information is to mine what you already have for possibilities. For example, say you've found an academic paper on the subject you're researching. This paper should contain a bibliography of what the author used for his or her research, which in turn you can then utilize to widen your stable of resources.
Direct Access To Databases
If you want to cut out the middleman and get directly to the academic mother lode, here are a few resources to check out:
The inforgraphic in this article was used with kind permission from Hack College. You can see the infographic in its entirety here: How to Get More Out Of Google.