Do your research. Look through the course catalog to see if there are any classes that interest you. But remember that no matter how interesting the subject matter of a class, a bad prof can make even the most fascinating subject a total bore.
Talk to your friends and older schoolmates. Ask about great profs they've have before, and get their help to pick a prof. Ask them what the prof did that made them such a great lecturer. Talk about their favorite college classes.
Look up professors online. There are many online websites to help you pick a prof. You can read professor reviews and find out more about the pros and cons of taking any college class with any specific professor.
Check to see if your school has a professor guide. Many colleges have student produced guides to professors and courses with course reviews and professor reviews available for you to read. These can be a great resource to pick a prof.