Before you decide on a topic, do some background research:
- Select a topic that genuinely interests you.
- Ask a research question about that topic.
- Do a variety of test searches to see what research has already been published on your topic.
- Broaden or narrow your topic as necessary.
When you are doing background research on your topic, consult reference sources. These can include encyclopedias and other reference works found in the library or online; and yes, in this preliminary phase of research you can use Wikipedia. However, NEVER cite Wikipedia as a reference for your research. Wikipedia is not a formally peer-reviewed resource, the authors are unknown, and content in Wikipedia changes over time.
Remember that your topic and your research question can change, especially if the topic is too broad (or too narrow), or if research on your particular topic has not yet been published.