There's a lot of interest around when is it right to use a section, section group, or notebook in OneNote to organize your information. I'll admit it can be very confusing so here's some rules of thumb I follow when managing my own.
- Use when you're likely to need to share content.
- Allows you to isolate materials around large topic areas (work vs. home, large projects, etc.)
- Good for materials you may not need to access all the time (open the notebook when you need it, close it when you don't)
- Useful for breaking down notebooks into logical groupings (work - meetings, notes, plans, schedules, etc.)
- Can be secured by password for better protection
- Can be color coded for easy reference
- When you need larger subdivisions in a notebook (Work - Projects (Section Group) - Project A (Section)).
- Helpful when archiving content into a master notebook
If you're organizing your personal content, don't worry about getting it right the first time. If you're organizing collaborative content, adding a page showing the organizational structure can be a boon to anyone using your notebook.