More than one meaning
A Book of Shadows may refer to a tradition-specific collection of ritual material, an individual's private notebook, or a contemporary publication using the phrase. These are different things with different histories and expectations of privacy.
Initiatory material may be restricted by a community's agreements. Reproducing private documents without authorization is inappropriate even if a copy can be found online.
A useful learning notebook
Students can create their own journal with dates, observations, research references, ritual reflections, questions and corrections. Label original ideas separately from published sources and material learned with permission.
A notebook becomes more valuable over time when it documents what changed in your thinking, not merely a list of purported correspondences.
We distinguish historical documentation from folklore, personal testimony, and religious interpretation. Traditions are diverse; no single account speaks for all practitioners.