Applications to be an Elite Notetaker open up a few weeks prior to the school year. By this point, you should know at least which courses you're taking already. We recommend you input the classes you are interested in uploading for, so that we can walk you through the process. When you sign up, it will ask you to enter your exam dates and other course info, but if you need time to decide or if you don't have all the information you need on hand, you can always go back to fill it out later.
If you decide mid-semester/quarter that you have a class that you feel would be a good fit for StudySoup, you are still welcome to start posting and selling for that course.