Start thinking about research early. It is best to begin your search for a lab the semester before you intend to register. It may take multiple contacts before you find a lab home.
Think about what you are interested in.
You probably have many different things that interest you. Really examine why you are interested in these topics. Look for overlap and similarities. These will help you focus in on a specific field that you would really like to explore.
Talk to people!
Talk to your advisors and professors. Tell them what you're interested in. They can help point you towards faculty members who are working on similar problems, including faculty in other departments that you might not have considered.
Talk to other students. Older students can offer suggestions about what classes to take, identify professors you might want to talk to and share how they found their research position.
Do some reading.
Check departmental websites and faculty research pages for descriptions of their research. Find something interesting? Go one step further, and read some of their work. Scholarly articles are written for other experts in the field, so don't worry if you don't understand everything. Read through the abstract and introduction and other parts that look interesting to you. This should help you determine if you are curious about the problems they are studying.
Attend events.
Connect with Natural Sciences students and faculty to learn more about research opportunities during the Natural Sciences Research Week, held each semester or attend campus-wide events, like the Office of Undergraduate Research and Inquiry's Discover Research Fair to hear about student research experiences in all disciplines. Events like these are great ways to learn about interesting research possibilities.