Often, the hardest part of research is getting started or developing a topic. Consider the following when you're developing your topic:
Interest. Pick a topic that's interesting to you. Research is much more enjoyable if you care about your topic.
Knowledge. You don't need to know much about your topic--even a little bit of knowledge, however, does help.
Explore. Look at your textbook or class notes. Talk with a friend or family member. Browse the table of contents of core sexuality journals: Sexuality & Culture, Studies in Gender & Sexuality, Journal of Psychology & Human Sexuality, Sexuality Research & Social Policy.
Focus. Make sure your topic is not too broad (sexual orientation) or too narrow (trans-gender discrimination in a small town in Wyoming). It's always a good idea to test drive a topic before you commit. Are you drowning in too many results? Or did you find very little information? After you've done a bit of research, it is common to find that you need to refine your topic
Guidelines. Read your assignment carefully. Must the topic be related to the course? Can you choose a topic? The assignment should provide some guidance in topic choice. If it doesn't, talk with either your professor or with a librarian.
Image source: Rapple, Brandon. Choosing a Topic. Boston College.