One of the big benefits of using the Family Tree Notebooks system is that it gives you a way to easily "make space" for each ancestor by creating a chapter of pages and documents tied together by that ancestor's index number. The index number can be assigned by you if you create your own index but most people use the pre-assigned index number found on the Family Tree Notebooks index.
The index also makes it easier for you to organize your digital genealogy files on your computer because you can use those index numbers to create folders for each ancestor. Just make a folder for your family tree notebook and inside that folder, create subfolders for each ancestor using the index number, surname, first name, and middle name.
Now that each ancestor has a folder, you can create subfolders inside that person's folder so you have a way to organize the different records/photos by the different types of life events. Don't forget to also create a folder for you to store your completed Family Tree Notebooks pages for that person.
I also use the index number in the file names for my digital genealogy documents/photos. The only difference is that I use underscores instead of spaces so that the file name doesn't get jumbled as I move it from place to place. I also add the record type at the end of the file name so I can easily scan a list of records and know if I'm looking at a birth record, a marriage record, a military record, etc.
Feeling a little lost? Check out this video for some help: