A small reference notebook
Choose a subject below. Each note can be read on its own.
Before opening a long text, write down one question you hope it can answer. That question gives a first pass some direction. It also helps you notice when a text belongs to a different subject and should be saved for another day.
A useful reference title names its subject in ordinary words. Add an author, date or edition when those details distinguish similar material. A folder full of clear names remains easier to browse than one that depends entirely on remembering when each file was saved.