I just find reliable sources. You can use the internet, a library, conduct interviews, watch documentaries, or whatever you feel is appropriate to teach you everything you need to know about your topic. Be an expert!
You can do research online very easily. However, you should be wary. Draw only from reliable sources like reputable newspapers, experts on the topic, government websites, or university websites. Look for information that lists other sources, since this will help back up any claims made by your source. These materials can also be acquired in print and the same precautions should be taken there.