If you don't upload at least 8 separate weeks of course notes, you will no longer be eligible for the $200 End-of-Semester Bonus. However, most semesters are 10-12 weeks long, so if you miss a week, it's not the end of the world.
Additionally, if you upload weekly notes, then you'll have a lot of material to pull from when it's time to create your study guides. Not to mention that it's just a good habit to be in!
You can upload only one set of notes per week, per course! StudySoup considers a week to be a Monday through Sunday period.
Uploading multiple sets of notes in one week or all 8 weeks of notes at the end of the semester will not qualify you for the End-of-Semester Bonus.