Using Notebooks
Phil wrote a great post here, summarizing when to use or not use Notebooks.
There's one "bug", however, in relation to the fourth reason to use Notebooks. Here's the reason as Phil puts it:
4. Organize: You want to create lots of notes and have them automatically organized. When you’re viewing a notebook, newly created notes will automatically be filed in that notebook. It’s currently not possible to have tags automatically applied to new notes. You can always bulk edit your notes when you’re done to add a tag and remove them from the notebook. In this way, notebooks can be a temporary tool for easier organization.
The bug appears when "viewing" more than one Notebook at a time (via multiple instances of the Notes Tool) and having a highlighting palette set to create highlights in the "Most Recent Notebook". Newly created highlights (created via the highlight palette or a hotkey) in this scenario get filed to the most recently filtered instance and may therefore not be the one you are currently viewing.