Your topic has to embrace the requirements of the assignment as well as what you are genuinely interested in. These resources should help you find a topic that is academic and relevant, and that inspires you. Also, please don't hesitate to talk with your teacher and your librarian to help you find the best topic for you.
Mindmapping is a good tool for brainstorming. Mind42 is free online mindmapping software. An added benefit to this tool is that you can share your mindmap with someone else and brainstorm together. Here's a tutorial on using mindmapping to start your research paper: http://www.library.arizona.edu/help/tutorials/mindMap/index.php
Wikipedia is an encyclopedia, but an encyclopedia that anyone can edit. While the quality is going up, it doesn't work on the traditional publication model. It does not depend on academic experts or editors. If you use a Wikipedia article, use your critical thinking skills to evaluate it: does the author have authority? is it well-written? does the information compare similarly to other information you read? is there a well-formed reference list? does the reference list have a variety of sources? Sometimes Wikipedia is useful to get ideas and point you to other resources, but you probably don't want to cite it in your reference list or paper
This LibGuide is adapted from Claire Murata's Research Guide (Shoreline Comminity College).
Encyclopedias give you the background, including major events, ideas, problems, and facts. They are found in both the online and print reference collections of the library. Read encyclopedia articles before you read scholarly journal articles, and you will have a better chance of understanding the specialized vocabulary that experts use with each other. Take a look at Credo Reference where you can draw information from over 500 reference books. Note the Concept Map tab to expand your idea.