If it's interesting enough, and/or "big, will read later" then I save a local copy (pdf, html, plain text or even an image).

Mostly organised in logical-to-me directory structure.

Local storage beats online-only in many ways, imho. Online content rots away over time. Whereas backing up local files is easy.

Beside that: browser bookmarks, simple note-taking app, and (last but not least) pen & paper.