Course material: Go back over lecture notes or textbook chapters to find a topic.
Brainstorming: Take the general topic and create a concept map for it. From there you may find some aspect of the topic you would like to explore.
News: Yahoo News, CNN.com, local broadcast news all cover recent events and may pique your interest for further exploration of the story.
Internet: There are many reliable educational and current event resources available on the Web that are excellent sources of ideas for selecting research topics. Keep in mind that because of the open nature of the Web, many resources vary in quality.