You have your question/problem formulated. What's next? Research.
Now you need to find out about your subject. You need background information before you move on to your next step, the hypothesis. What other research or experimentation is out there? Will this influence your experiment?
Where do you find this background information?
Video by Chris Bourg, Stanford University Library
Choose your sources wisely. Make sure you do enough research, but stay focused on your problem.
How do I know if my sources are good? Useful links.