Adding a Checkbox to Text
If your section of your notebook is a to-do list, you can put a checkbox against each task, so that they can be marked as complete as time progresses.
Select the text for the text box first. You can then either use CTRL+1 or click on To Do (CTRL+1) in the Tags group of the Home tab on the ribbon.
This will display a check box in front of your text. Click on it to check or uncheck it.