Grimmoire

It's a book, a story book, and not only a spellbook.
In the grimmoire, the witch will copy her recipes, her spells and rituals, but also the story of what she learned.

You can have personal grimmoires or coven grimmoires.
Finding one of them is precious as it is full of interesting knowledge.

Even though some are visible on the Net nowadays, I would not advise to use spells and rituals from other witches, at least not without studying them and modify them to fit your needs.
working yourself on a ritual will bring your energy into it and will have that much better results.

But you will find researches, stories and analysis from other practitionners, which is always valuable information.

Blessed be friends,
Albus Draco,
The knowledge addicted mystical creature